Since September 11, 2001, a significant portion of US public policy has focused upon the threat of terrorism. Following the attacks, the need for increased attention to counterterrorism resulted in substantial allocations of public funding toward these initiatives. Yet, researchers conducting systematic reviews of the literature surrounding counterterrorism strategies have found that very few rigorous evaluations of such strategies actually exist, notwithstanding these substantial expenditures (Lum, Kennedy, & Sherley, 2006). Even more surprisingly, this shortage of research persists despite the considerable amount of scholarly attention focused on producing other types of publications related to terrorism. An example of this can be seen with respect to the literature surrounding terror-related legal issues. Post-9/11 legal questions have often been central to policy debates regarding terrorism; some examples of key issues include those surrounding harsh interrogation methods, indefinite detentions, warrantless wiretapping, and extraordinary renditions, to name only a few. However, while legal scholars and commentators have energetically published more traditional doctrinal analyses of law, few empirical studies of post-9/11 legal issues have been conducted and even fewer of these have attempted to evaluate specific counterterrorism strategies.

One explanation for this may stem from the fact that mainstream legal scholarship has not traditionally employed the methodologies of social science, such as experiments, surveys, or the statistical analysis of data. Additionally, until relatively recently, few scholars have been cross-trained to possess both legal and social scientific expertise. Over time, this is changing, as greater numbers of scholars pursue joint degree programs or opt to embrace the perspectives of fields like law and society and empirical legal studies. In many ways, then, the existence of little empirical research and even fewer evaluation projects related to law and terrorism is perhaps merely reflective of the general orientation of legal scholarship. However, given the importance of the topic of counterterrorism and the central role that legal issues have played in the post-9/11 era, the need for research which integrates legal scholarship to a greater degree with the more policy-oriented paradigm of evidence-based counterterrorism is quite pressing. Moreover, though scholars in fields like law and society are producing a great deal of impressive scholarship related to ­terrorism, few law and society scholars have attempted outcome evaluations of ­specific terror-related policies.

This chapter will explore further some of the post-9/11 empirical research related to law and legal institutions. Though very little of the existing empirical research in this area purports to evaluate specific counterterrorism strategies, this literature will be examined from the viewpoint of building an evidence base that can be utilized by both policy makers and also by scholars interested in future research. Building from the foundation of current empirical work, each section will offer some suggestions for future directions in scholarship. One important note is that this chapter is not meant to represent an exhaustive review of the scholarship related to law and terrorism. Rather, this discussion is meant to provide some examples of areas where the lens of evidence-based counterterrorism might aid interested scholars in thinking about future work.

Building an Evidence Base Through Social Science

In highlighting the lack of empirical work in this area, this discussion is not meant to diminish the value of nonempirical legal scholarship. Rather, doctrinal work is important both for its independent contributions and also for the ways that it can inform social science about the law. In the social sciences, much of the empirical scholarship related to legal issues is routinely conducted by nonlawyers. As a result, doctrinal analyses of law are a key foundation for almost any social scientific work. Even where researchers conducting social scientific studies of law possess a high level of legal expertise, doctrinal analyses of legal issues help social scientists to understand the views of experts actually immersed in these issues. For the most positive outcomes from research, these communities must work synergistically, each relying upon the other to broaden its understanding.

Yet, there is also a role for social science to play in understanding the operation of law, particularly with respect to a problem like that created by terrorism. When confronting the threat of terrorism, our hope is that law and legal institutions will prove effective tools to aid in a variety of counterterrorism efforts. Additionally, our society seeks to employ counterterrorism strategies without violating our laws or undermining longstanding institutions or legal norms. However, to accomplish any of these goals, law-related terrorism scholarship must be focused not only on issues of “black letter” law, but also on evaluations of law’s operations, effectiveness, and impacts. Without empirical research, we cannot systematically assess how effective our policy choices have been. In making these assessments, there are a number of different types of studies that are needed.

First, as is clear from the discussion so far, additional empirical legal research which systematically evaluates post-9/11 policy choices is necessary. Since 9/11, our leaders have been consistently challenged by how to adapt legal processes and institutions to conform to the demands of terrorism, yet existing social science research tells us relatively little about the success of these efforts. Some examples of this type of research are discussed below, but, to date, social scientific evaluations of legal policy are exceedingly sparse. There are a few existing examples of this type of research in related fields, such as policing (Huq & Muller, 2008; Kalyvas, 2006; Weisburd, Feucht, Hakimi, Perry, & Mock, 2009), but even accounting for related studies, research of this type is in relatively short supply. In addition to evaluations of legal policy, empirical research is also needed to evaluate other types of policies that have legal implications. For example, an evaluation of new technologies in use by law enforcement for counterterrorism purposes might not seem at first to be an issue for empirical legal researchers. However, the use of such technologies may have implications for privacy rights and also may influence ongoing citizen expectations of privacy. One example of this is the use of license plate recognition technology by law enforcement (Lum, Merola, Willis-Hibdon, & Cave, 2010). Empirical legal scholars have a role to play in comprehensive evaluations of such technologies. To date, few of these types of technological evaluations (integrating empirical legal evaluations) have been conducted. Empirical evaluations of policy can be proactive (for example, completed in an experimental or lab setting) or these studies can involve the retroactive evaluation of policies. However, a greater effort to integrate legal scholarship with other types of evaluative literature would aid counterterrorism efforts and may also make it more likely that legal ­concerns are considered when policy is developed.

In addition to evaluating specific counterterrorism measures, scholars in the field of law and terrorism can also add to the evidence base by focusing on systematically assessing expert opinion about these policies. For example, a tremendous amount of effort has been expended debating the relative merits of policy decisions like the use of Guantanamo Bay as a detention center or the propriety of civilian trials as compared with military tribunals. However, few attempts have been made to systematically assess the views of legal experts (or other types of experts, for that matter) regarding particular policies, nor how these experts would evaluate critical issues. Perhaps paradoxically, the large majority of opinion research about terrorism (even with respect to legal issues) focuses on the opinions of average Americans. Of course, in a democratic system, the study of public opinion is very important, but public opinion studies often tell us little about the relative merits of policy choices. As an example, since 9/11, our society has frequently debated the proper venue for trying terror suspects and the question of whether or not it would be wise to detain these individuals inside the United States to await trial. Yet, to the author’s knowledge, there is only one study (currently in progress) that systematically assesses opinions and gathers policy insights on this topic from those with expertise in the field of corrections (Merola et al., 2011). The vantage point of evidence-based counterterrorism is particularly helpful in focusing scholarship on the ways in which scholars can support policy more effectively. In this way, evaluation research helps to provide a bridge between legal scholarship and policy makers.

As longer-term questions, researchers might also wonder about the impact of a variety of terror-related legal policies on the continuing legitimacy of legal institutions in the United States or on the maintenance of legal norms. At present, too little empirical research assesses these questions. However, it is important to note here that one study does associate beliefs about policing strategies with the willingness to cooperate with police in their conduct of counterterrorism operations (Tyler, Schulhofer, & Huq, 2010). Also, there is some research (detailed below) that examines developments in public support for the norm of expansive civil liberties in the post-9/11 United States. Of course, Americans hope not to violate the traditional norms of the United States nor to erode the legitimacy of US institutions with counterterrorism operations. However, without empirical evaluations of particular policies or interventions, researchers neglect to make use of one of the most effective tools of systematic assessment that we possess.

Greater attention to creating an empirical evidence base upon which policy makers can draw in times of crisis can only increase the real world impact of our scholarship. A fundamental tenet of the evidence-based paradigm is to forge a closer link between researchers and practitioners, with the goal of making policy more effective (Pfeffer & Sutton, 2006). This paradigm demands that practitioners account for the findings of scholarly research while developing policy, but, in this way, the paradigm also provides a bridge for researchers to speak to practitioners and to become a greater force in policy development (Pfeffer & Sutton, 2006; Rousseau, 2006). The next few sections of this chapter will extend this theme further through a discussion of some of the existing empirical research. Though comparatively little empirical research exists on these topics, a number of studies have presented findings that can be useful in framing future evidence-based counterterrorism policy and research.

Empirical Evaluations of Legal Policy in Response to Terrorism

Since 9/11, government actors have been faced with a stunning array of policy decisions related to counterterrorism, many of which directly involve law, legal norms, or legal institutions. In fact, many of our most basic rights have been challenged by the events of the post-9/11 era. Additionally, in response to the threat, our nation has put into place a host of new legal provisions, including those contained in the much-debated USA-PATRIOT Act (2001). It is logical that social science research would be an important tool for evaluating the effectiveness and impacts of these post-9/11 legal policies, particularly when the stakes of counterterrorism are so high.

Yet, to date, little empirical research has focused on assessing the legal aspects of policies enacted in response to terrorism. In fact, in a search, the author uncovered only a small number of empirical articles that have assessed the impact or functioning of any law-related policy connected with counterterrorism. As an example, one of these articles examines the passage of state laws in the late 1990s which prohibited the filing of frivolous liens (Chamberlain & Haider-Markel, 2005). According to the authors, in many cases, such laws were passed in order to deter Common Law groups from engaging in domestic “paper terrorism” by filing frivolous liens against elected officials. These officials usually had been “convicted” of crimes and “sentenced” to pay fines in underground courts established by these groups (Chamberlain & Haider-Markel). Though this study examines pre-9/11 data, the authors argue that their work provides lessons for post-9/11 state-level policy (Chamberlain & Haider-Markel, p. 449). This study provides an interesting example of scholars utilizing pre-9/11 data to conduct studies which may bear upon the post-9/11 world.

A second article, published in 2008, examines the 9/11 victims compensation fund (Hadfield, 2008). Hadfield highlights a number of concerns about the fund, including “a deeply troubling trade-off between money and a host of nonmonetary values that respondents thought they might obtain from litigation” (Hadfield, p. 647). Though the fund was meant to compensate victims of the attacks, Hadfield finds that those legally entitled to relief through the fund often delayed applying for this relief because they thought they might obtain a nonmonetary good (such as policy change) by waiting or going to court. Still other victims hoped to gain “information from otherwise inaccessible sources, [such as] the decision makers who determined airline and World Trade Center fire safety procedures” through a lawsuit (Hadfield, p. 647). Even though a streamlined legal remedy was designed following 9/11, this research uncovered potential obstacles in its operation and to the operation of future funds of the sort, namely that victims often framed the right to go to court as a responsibility of good citizenship following a national tragedy (Hadfield, p. 673).

This study raises an important point with respect to why additional social science research is needed when so much traditional, doctrinal legal research has already been published in relation to the topic of terrorism. Social science is particularly useful for uncovering obstacles or issues that impact the functioning of social processes (in this case, legal processes). It is certainly true that more traditional, nonempirical legal analyses are also useful and even that such analyses may arrive at the same conclusions as an empirical study. Yet, social science allows for the systematic assessment of potential issues, often providing statistically reliable evidence regarding just how frequently a particular problem occurs and also what types of factors influence the process.

Another example of this can be seen with respect to an article published in 1993 (Enders & Sandler, 1993). Enders and Sandler used time series analysis to examine whether or not two counterterrorism laws enacted in 1984 actually prevented attacks on US interests (Enders & Sandler). Specifically, the first law put into place more severe penalties for acts of hostage-taking, destroying aircraft or airport facilities, and using a weapon on an aircraft (Enders & Sandler, p. 834). The second law allowed the US attorney general to give rewards to those providing information about terrorism (Enders & Sandler, p. 834). In the end, the results of the analysis suggested that these laws were not effective in reducing terror attacks on US interests in the years following their enactment. Yet, knowledge of this result would not have been possible without utilizing social scientific methods (in this case, statistical analysis) to examine a large dataset of attacks on US interests over the course of multiple years.

It is clear from this discussion that the research which evaluates specific legal policies enacted for counterterrorism purposes is limited. In many regards, this is not surprising, as others have provided evidence that empirical research which evaluates counterterrorism measures more generally is extremely sparse (Lum et al., 2006). In addition to evaluations of legal policy, research is needed which assesses nonlegal policies that have implications for law or legal norms. In both cases, a greater effort to integrate legal scholarship with other types of policy-relevant outcome evaluations also seems likely to increase the consideration of legal issues when policy is developed. Since empirical research evaluating specific post-9/11 legal policies is so scarce, it will also be necessary to expand the scope of this discussion during the next sections of this chapter. Perhaps there are additional areas of law-related empirical research that (while not evaluating specific laws or policies) provide a ­useful foundation for scholars wishing to understand and expand the evidence base in this field.

Research Related to Changes in Public Support for Civil Liberties Following 9/11

The largest quantity of existing empirical research related to the topic of law and terrorism investigates the potential for alterations in public support for expansive civil liberties following 9/11. It is not that surprising that researchers have opted to focus on this topic, since questions about the proper scope of post-9/11 civil liberties have been an important part of the public discourse since the attacks. Following 9/11, there existed a sense of concern that Americans might turn away from their historical commitments to broad-based civil liberties in an attempt to bolster security in the face of terrorism. According to a key researcher in this area, “at no other time in American history [did] citizens [believe] that they would have to sacrifice a certain measure of freedom and liberty to be safe and secure. Cherished values of liberty and security, usually unnoticed, taken for granted, now had tangible consequences” (Davis, 2007, p. 218). Researchers interested in examining questions of public support for civil liberties also possessed a fairly extensive pre-9/11 foundation of empirical research upon which to build (Marcus, Sullivan, Theiss-Morse, & Wood, 1995; McClosky & Brill, 1983; Prothro & Grigg, 1963; Stouffer, 1955; Sullivan, Piereson, & Marcus, 1979).

Much of this pre-existing empirical research examined what has been termed “political tolerance” or the willingness of the American public to support expansive civil liberties protections for members of groups holding beliefs outside of the mainstream of society. Early work in this field measured Americans’ attitudes toward extending rights to those who did not “conform” to society, most frequently referencing communists, socialists, and atheists (Stouffer, 1955). According to Stouffer, although large numbers of Americans endorsed the ideals of civil liberties in the abstract, the public exhibited resistance to these principles with respect to their application to actual situations and specific nonconforming groups (1955). In fact, the sheer prevalence of political intolerance present in early data on the subject forced researchers to question the extent to which Americans actually supported the free exercise of civil liberties. Over the course of decades, numerous scholars confirmed these findings, rendering the lack of political tolerance a persistent contradiction within the context of the otherwise robustness of American democracy (McClosky & Brill, 1983; Prothro & Grigg, 1963, Sullivan, Piereson, & Marcus, 1979).

Over time, researchers in this field learned quite a bit about the demographic and other individual-level characteristics that are associated with an increased likelihood that an individual will be willing to support robust civil liberties. For example, a number of researchers have provided evidence that better-educated, more politically active citizens are more supportive of civil liberties (Davis, 1975; Gibson, 1987; Lawrence, 1976; McClosky & Brill, 1983; McClosky & Zaller, 1984; Nunn, Crockett, & Williams, 1978; Prothro & Grigg, 1963; Sniderman, Tetlock, Glaser, Green, & Hout, 1989; Stouffer, 1955; Sullivan et al., 1982). Further, those living in more urban areas, who are younger and who are less conservative in ideology, have also been more likely to support robust civil liberties in a number of studies (McClosky & Brill, 1983; McClosky & Zaller, 1984; Sniderman et al., 1989; Stouffer, 1955; Sullivan et al., 1982). However, a number of psychological traits, such as dogmatism (Stouffer, 1955), neuroticism, and extraversion (Marcus et al., 1995), seem to be associated with lowered support for civil liberties.

More recently, in addition to examining the level of political tolerance present in the American public and associating variations in tolerance with specific individual characteristics, scholars have also attempted to understand the mental processes which lead to decisions supportive of civil liberties (Bobo & Licari, 1989; Kuklinski, Riggle, Ottati, Schwarz, & Wyer, 1991). For example, following a series of experiments embedded within surveys, one group of scholars provided evidence that the content of information can alter citizen support for the maintenance of broad civil liberties guarantees (Marcus et al., 1995, pp. 78–79). Marcus et al. theorized that this effect occurs when individuals feel threatened by the information that they have encountered regarding a disliked group’s activities. And, since threat is an integral part of the model (Marcus et al., 1995; Stouffer, 1955), this research certainly raises questions about the potential impact of post-9/11 debates surrounding the proper scope of civil liberties on a public confronted with large amounts of threatening information related to terrorism (Davis, 2007; Merola, 2007). Though much of the research in this field was conducted prior to 9/11 (and, as a result, did not refer directly to terrorism), it has provided a strong theoretical foundation for examinations of the impact of terrorism information upon civil liberties during the post-9/11 era (Davis, 2007; Davis & Silver, 2004; Merola, 2007, 2011; Scheufele, Nisbet, & Ostman, 2005).

Authors working in this area of post-9/11 law-related scholarship have argued that the terror attacks “dramatically changed the political context” in the United States (Sullivan & Hendriks, 2009, p. 375). This is particularly important in light of the research mentioned above which has demonstrated that decisions about civil liberties are significantly influenced by the information environment (Marcus et al., 1995). Certainly, this is not to say that individual-level traits, socialization, or other long-term individual predispositions cease to play a significant role in support for civil liberties in times of crisis. Rather, it has been demonstrated in survey-experimental research that all of these influences – long-term “standing” decisions about civil ­liberties, individual traits, and the content of information – significantly impact views about the proper scope of rights (Marcus et al., 1995).

Yet, the environment is also influential. Despite the fact that Americans are socialized to respect assertions of rights and to value equality before the law, even a single encounter with certain types of negative, group-specific, or other information may lead to qualifications in support for expansive civil liberties, a key norm of the American legal system (Marcus et al., 1995; Nelson, Clawson, & Oxley, 1997). Following 9/11, the American public watched news coverage in record numbers (Althaus, 2002). Given the amount of discussion that has taken place in the media and also in the public debate regarding “balancing civil liberties with security,” it is logical to assume that Americans’ assessments of the proper scope of rights may have undergone some revision.

Indeed, the measurements of support for civil liberties taken directly following the attacks seemed to validate concerns that extensive changes had taken place within our society in this regard. For example, in their review of this area of research, Sullivan and Hendriks report the results of a Pew Research Center poll that found that 55% of respondents agreed that sacrificing civil liberties would be necessary in order to curb terrorism, whereas that number was 29% when measured in 1997 (2008, p. 380, citing Pew Research Center, 2001). And, equally consequential in times of crisis, post-9/11 researchers in this field have provided evidence of a substantial relationship between perceptions of terrorist threat and the willingness to sacrifice civil liberties (Davis, 2007; Huddy, Feldman, Capelos, & Provost, 2002). In fact, in post-9/11 models, perception of the threat of terrorism has been shown to be of greater or equal consequence to highly influential individual-level variables, such as respondent ideology, level of education, degree of authoritarianism, and media use (Huddy, Feldman, & Taber, 2005; Nisbet, Ostman, & Shanahan, 2008). Empirical research has also provided evidence that threat cues rose by at least 66% in a random sample of post-9/11 media coverage of civil liberties issues and that this increase continued for several years following the attacks (Merola, 2011). Further, this transmission of threat may be particularly significant, as researchers have also argued that it is a sense of societal (as opposed to personal) threat from terrorism that is most potent when individuals make decisions about the proper scope of civil liberties (Davis, 2007; Gibson & Gouws, 2003; Huddy et al., 2002).

These findings suggest the possibility for dramatic changes to key democratic principles following serious attacks. Yet, research completed directly following the attacks also provided some indications that predictions of large scale change should be approached cautiously. For example, even in the context of a willingness on the part of large percentages of Americans to agree to post-9/11 constrictions of civil liberties in principle, the percentage of Americans willing to cede specific rights in order to combat terrorism often diminished in response to more specific survey questions (Davis, 2007). Additionally, measurements taken later in the post-9/11 period seem to suggest that conceptions of rights eventually began to stabilize, at least in the sense that fewer Americans readily agreed to broad-based constrictions of civil liberties in surveys (Davis, 2007; Sullivan & Hendriks, 2009, p. 387). And, as time passed, greater numbers of Americans likewise expressed concerns about increasing the government’s power too much, as trust in government declined (Davis, 2007). Some explanations for this stabilization suggested by the literature have been this decline in trust in government (Davis), the lessening of perceived threat over time (Nisbet & Shanahan, 2004), and fewer elite cues about threat being transmitted in the popular media as the post-9/11 period progressed (Merola, 2011), to name but a few.

Unfortunately, though, polls which have suggested that Americans are “back to normal” in terms of their responses to survey questions about civil liberties may still mask some substantial societal changes. First, as Sullivan and Hendriks argue, these surveys may not account for significant changes in law, which remain in force even after a period of threat has passed (2009). These changes “can shape politics for years to come” (Sullivan & Hendriks, 2009, p. 388) and current crises may also shape expectations about the handling of future crises (Merola, 2007, p. 223). Davis argues that Americans will be more wary of future claims that rights need to be constricted in times of threat, now that they have experienced the post-9/11 era (2007, p. 224). Yet, the opposite may also occur in some cases. Some suggestions made by political leaders regarding the curtailment of rights to meet a crisis situation may no longer be as shocking to the American conscience as they once were (Merola, 2007). Moreover, the notion that conceptions of rights may eventually “rebound” once a threat dissipates may not be useful in the event of a series of attacks or serious crises.

Additionally, even where the literature in this field is relatively complete, it has often not been used as a platform for designing and testing interventions nor has it been linked to policy which may curtail some of the effects of terror attacks on the public. For example, a key finding of the political tolerance literature seems to be how significantly the content of information influences the public in times of threat (Marcus et al., 1995; Merola, 2007). Yet, though a number of studies have examined the content of media coverage related to terrorism more generally, little research has investigated the framing of legal issues since 9/11.

There is one study which investigates alterations in print and broadcast media content related to civil liberties before and after September 11, 2001 (Merola, 2011). The study focuses specifically upon the types of content (such as threatening information, group-specific information, and contextual information) that prior experimental research has suggested may influence individual decision-making concerning civil liberties. Overall, after examining the post-9/11 media coverage, the study finds the frequent presence of types of information that the experimental literature has suggested tends to decrease support for civil liberties (such as threat language) and the infrequent presence of the types of information which may have a protective effect (such as reminders about the American tradition of expansive civil liberties) (Merola). However, the study also finds significant differences between the types of content routinely found in print media and those contained in broadcast media, with the broadcast far more likely to contain content that appears destructive to the norm of expansive civil liberties in experiments (Merola). These results are also consistent with another study that suggests that members of the public who frequently consumed print media remained more supportive of traditional norms of expansive civil liberties than those who frequently watched national television news (Scheufele et al., 2005).

Taken together, this research suggests that types of information and media choices may have real consequences for how a populace grapples with the after effects of a terrorist attack. Yet, to date, researchers have largely not linked research on information to support for civil liberties, legal policy, or other effects, such as alterations in the legitimacy of legal institutions in the eyes of the public. The link with information is particularly important, since most members of the US public were not direct victims of the attacks of 9/11, but rather experienced the threat entirely through the media. In order to understand the impacts of terrorism on the public, we must understand the content and influences of messages from media and other elites that reach the public about terrorist events.

Additionally, this raises perhaps an even more salient point. If information can negatively impact legal norms, can information also be used to protect communities? Of course, the need for research regarding how to make communities more resilient extends beyond questions related to law and rights. Researchers in other fields have often grappled with this issue since 9/11 (Norris, Tracy, & Galea, 2009; Pfefferbaum, 2009). Yet, in the context of rights, can interested researchers also work proactively to examine the ways in which information or other counter measures may make communities more resilient to terrorism? Currently, this literature provides a great deal of evidence regarding the personality traits and circumstances that correlate with continued support for civil liberties and many of these relationships have persisted following 9/11. Yet, research in the field has generally not been translated into particular policy suggestions or interventions that can protect legal norms, nor has the field examined information’s impacts on opinion about other legal norms or legal institutions. To date, there is one experimental study that has reported a potential protective effect for certain types of information (Merola, 2007). In this case, in a survey-experiment utilizing students, a treatment group exposed to information reminding participants of the American tradition of expansive civil liberties expressed greater support for civil liberties in the context of hypothetical terror attack scenarios than did a group that received information advocating dispensing with civil liberties as a response to terrorism (Merola). In each scenario, this information was delivered to participants via a person-on-the-street interview during a fictional nightly newscast.

This study tested only one type of information, but there may be others which could be utilized by government officials to serve a protective function in times of crisis. At least, researchers might be able to provide some guidance to government officials regarding types of information to avoid in order not to exacerbate a crisis. Davis (2007) argues that discussion of many of the policy initiatives promulgated by government following 9/11 – though intended to protect Americans – actually compounded the anxiety that Americans felt. Indeed, it is possible that some of our own actions or perhaps the content of our discourse actually made the impacts of the attacks even more severe than they might otherwise have been. Additional research related to how to utilize information in the most beneficial way (or, at least, not in a harmful way) would be an important contribution.

Also, the methodologies used frequently by pre-9/11 researchers studying support for civil liberties – that of the experiment or the embedded survey-experiment – could be particularly helpful to researchers. In the case of a survey-experiment, in addition to the data derived from the survey itself, an embedded experiment allows researchers to directly test the impact of a particular intervention, such as the influence of specific categories of information on decision-making by members of the public. At present, experiments are not used very frequently to examine law-related research questions (with respect to terrorism or otherwise). Yet, a close causal link between an intervention or event and an outcome can be demonstrated in an experiment. In turn, the ability for researchers to provide strong evidence of such a causal link suggests that experimental methodologies represent an important tool for researchers interested in furthering evidence-based policy.

Elite Discourse, Opinions, and Cues

The previous section of this chapter questioned the degree to which we understand the impacts of discourse regarding many of the policy decisions made following 9/11. In the last section, we explored the considerable empirical research devoted to understanding support of civil liberties among members of the general public. Indeed, as discussed above, some researchers have focused specifically on examining public support for civil liberties in the post-9/11 era and have even found that a significant portion of the pre-9/11 research remains valid. In comparison, however, we actually know very little about elite discourse, opinions, or even the role of elites (even legal elites) in shaping support for civil liberties and legal policy in times of crisis (Merola, 2007, 2011; Sullivan & Hendriks, 2009). Generally, this is not surprising, as relatively few elite opinion studies exist within the empirical legal scholarship more broadly. Perhaps paradoxically given the expertise required to understand many terror-related issues, the majority of post-9/11 opinion research has focused on the public.

Yet, particularly with respect to an issue like terrorism which raises complex policy questions, it is important to understand elite opinion in order to better comprehend the process by which the public acquires its information and policy preferences about terrorism. Seminal research in the field of communications has argued that “if we are interested in the quality of information reaching the public, we must understand how it is manufactured, which is to say, we must understand the politics of expert communities as they relate to the generation and diffusion of knowledge claims, policy recommendations, and general frames of reference” (Zaller, 1992, p. 319). Legal elites are no exception, yet their role in the framing and diffusion of post-9/11 legal information (such as that related to security and civil liberties) has largely not been assessed systematically. The same is also true for other types of elites, particularly with respect to legal issues.

To date, two studies of the post-9/11 behavior and opinions of legal elites have been conducted that are relevant to this discussion. The first study involved a content analysis of the legal community’s discourse about civil liberties, as published in law review articles during the post-9/11 period (Merola, 2007, 2008). The goal of the analysis was to examine the role that these elites have played in either supporting or defending civil liberties during the post-9/11 period, since a number of scholarly articles have either explicitly or implicitly argued that elites play an important role in the maintenance of democratic norms in times of crisis (McClosky, 1964; McClosky & Brill, 1983).

After examining the language in a large sample of law review articles related to post-9/11 civil liberties, the study found that legal elites have incorporated threat information into this professional discourse with relative frequency, at times even more so than did some media sources (Merola, 2008). This is important both as a barometer of the impact of the terror crisis on the legal community and also as information ultimately communicated to policy makers and to members of the public. For most of the post-9/11 period, this attentiveness to the threat on the part of legal elites was also combined with increased attempts at opinion leadership; yet, on average, law review articles employed relatively deferential language until the year 2006. Following 2006, the language became increasingly less deferential. As a result, the study found evidence to support the hypothesis that legal elites mounted a vigorous defense of civil liberties in their discourse following 9/11. However, this finding must also be interpreted cautiously, given the results with respect to threat and deference that were seen in the years directly following 9/11.

The second article investigates the opinions of legal elites directly through a survey on the topics of post-9/11 civil liberties and legal policy (Merola, 2009). Elites in the legal community are often assumed to be unwavering in their defense of robust legal institutions and expansive civil liberties (McClosky & Brill, 1983). However, few studies have specifically examined these questions by surveying an elite sample. Instead, these viewpoints are most often attributed to members of the legal community as a result of their professional training, socialization, and high level of education (McClosky & Brill). Since numerous studies have demonstrated that higher levels of education are associated with stronger support for civil liberties (Davis, 1975; Gibson, 1987; Lawrence, 1976; McClosky & Brill, 1983; McClosky & Zaller, 1984; Nunn et al., 1978; Prothro & Grigg, 1963; Sniderman et al., 1989; Stouffer, 1955; Sullivan et al., 1982), it has been largely assumed that this evidence translates into a depth of knowledge about the views of the legal community.

Yet, attorneys were not immune to the threat or anxiety that was so prevalent in the remainder of our society after 9/11. Legal elites, like all Americans, were forced by the ongoing terror crisis to regularly consider the ramifications of “trading” civil liberties for enhanced security. The experimental research in the field of political tolerance would certainly seem to suggest that the commitment of elites (including legal elites) to expansive civil liberties is more durable than the commitment of the general public in the face of threat (McClosky, 1964). And, generally, this survey found legal elites to be very supportive of civil liberties in 2008. However, following an experiment, these individuals also were influenced by the content of terrorism information (Merola, 2009). In fact, despite their high levels of education and the possession of subject-matter expertise, the mere mention of “terrorism” was associated with decreases in support for civil liberties among legal elite respondents. Though perhaps not to the degree that would be expected in a sample of the general public, these decreases were significant (Merola). This result demonstrated that (much like the nonelite individuals in other political tolerance experiments) the terror threat was still quite salient to members of the legal community and that their education and expertise did not act as a complete barrier to the effects of terror-related information. Additionally, the survey yielded some results suggesting that the elite respondents were more willing to accept instances of racial profiling (particularly for those appearing to be Middle Eastern and at airports) than other abridgements of civil liberties discussed on the survey (Merola).

Scholars in the field of law and terrorism can add to the evidence base surrounding terror-related legal questions by focusing more attention on the opinions of elites, particularly legal elites. With respect to many post-9/11 policies, a considerable amount of public debate has focused on the relative merits of different choices, such as decisions about where to try terror suspects. However, few attempts have been made to assess the views of legal or other experts systematically, leaving an important potential source of guidance for policy makers underdeveloped. Given their professional expertise, systematic assessments of the views of the legal community seem a valuable resource for policy makers who often do not possess this specialized knowledge. In addition to evaluations of legal policy, systematic investigations of the views of experts may help policy makers to recognize potential issues or to eliminate certain policy choices as infeasible or ineffective. The vantage point of evidence-based counterterrorism research is particularly helpful in focusing scholars on the ways that their work may be linked with decision makers. In this way, evaluation research helps to make scholarship more relevant while making terror policy more effective.

Research Related to Executive Authority and Separation of Powers

The scope of executive authority emerged as one of the key constitutional questions during the post-9/11 period. Like many of the topics discussed in this chapter, a good deal of traditional legal scholarship has been published concerning the proper exercise of post-9/11 executive authority. Specifically, there was much discussion in the legal scholarship regarding the president as “unitary executive” (Scheuerman, 2006). The phrase “unitary executive” encompasses a view that all executive authority must be controlled by the President and may not be interfered with by other branches of government, particularly in the area of national security (Scheuerman). The scope of executive authority became a key issue of the post-9/11 era because executive authority was implicated directly in many of the salient policy issues of the time. For example, the question of whether or not the President and armed forces retained exclusive control over the detainees at Guantanamo Bay (or if these individuals could avail themselves of habeas corpus review by federal courts) became an important issue during the administration of George W. Bush.

A small number of researchers have examined issues related to separation of powers following 9/11 through empirical studies. These scholars have done so through examinations of the functioning of separation of powers during wartime. Historically, the prevailing view of separation of powers research has been that the legislative and judicial branches of the government have a tendency to defer to the executive during times of crisis, particularly in the foreign policy realm (Ducat & Dudley, 1989; Yates & Whitford, 1998). With respect to the question of judicial deference, recent studies of judicial voting have supported this view. For example, Epstein et al. have provided evidence that US Supreme Court justices decide cases related to civil liberties in a more conservative manner when the nation is at war (Epstein, Ho, King, & Segal, 2005). According to the authors, this phenomenon actually occurs to the greatest extent when the case at issue does not directly implicate the war (Epstein et al.).

Another study by Clark also confirms some of these findings (2006). Clark demonstrates that judicial preferences seem to undergo a fundamental shift in criminal cases during times of war, but that there is no evidence that judicial preferences change in other types of cases. Rather, this study suggests that judicial decision-making in noncriminal cases remains unaltered during times of war (Clark, 2006). For this reason, Clark argues that “concerns about judicial deference to the executive during times of war may not be as serious as conventional wisdom suggests” (Clark, p. 398). Clark’s research goes a long way toward confirming that, at least in terms of noncriminal cases, the separation of powers – a cornerstone principle of American government – remains intact in times of war. Though the two studies described above do not focus solely on changes in judicial decision-making during the post-9/11 period, both of these articles consider the “war on terrorism” within their models.

For those researchers interested in evidence-based counterterrorism related to law and legal institutions, these findings represent an important foundation. Though not tests of counterterrorism measures, these studies begin to construct an evidence base regarding how fundamental American legal principles fare when the country is under attack or in grave crisis. A future direction of research might be to expand upon these findings and to think about how these studies and others might inform our thinking regarding the best ways to protect fundamental aspects of our system during times of extreme threat. Empirical researchers might compare the post-9/11 time period explicitly to other wars and assess the differences that occur in the functioning of legal institutions when society is under threat specifically from terrorism.

Additionally, as mentioned in the last section, scholars could focus a bit more on assessing issues like the proper scope of executive authority in times of crisis through expert opinion studies. Though many analyses of issues related to separation of powers have been published by legal experts since 9/11, expert opinions about specific policies have generally not been assessed systematically. One existing paper (described in greater detail above) seeks to do that by examining views of policy alternatives through an expert survey of attorneys (Merola, 2009). In a survey of private attorneys and law professors with expertise in constitutional law, more than 83% of respondents indicated that they felt that the scope of executive authority had been expanded too far since 9/11. Further, similarly large majorities of these respondents indicated that terror suspects should not be treated as illegal enemy combatants and that acts of terror should be treated as crimes and not as acts of war (Merola). As policy makers choose between alternatives – such as continuing the detention of terror suspects at Guantanamo Bay or their relocation to the United States – the systematic assessment of expert opinion on the topic could help to guide decision-making.

Another article in progress (also mentioned briefly above) attempts to begin to construct an evidence base in this area through an investigation of the feasibility of policy alternatives to unfettered executive detention at Guantanamo Bay. For example, one alternative that has been quite controversial is the relocation of remaining detainees to US soil. Yet, at this point, social scientific evidence regarding the feasibility of this course of action is extremely limited. For example, there are currently very few evidence-based studies which attempt to assess the challenges of incarcerating religious extremists in civilian prison facilities. Some of the analytical literature surrounding this issue questions the feasibility of housing these prisoners either as a single group or in a configuration where these individuals might encounter other prisoners (Hannah, Clutterbuck, & Rubin, 2008). If housed as an isolated group, the concern is that these prisoners would grow in strength with increased numbers and through isolation from nonextremists. If dispersed throughout a prison containing other inmates, the concern is that these prisoners might convert others to their radical beliefs.

Recently, the author of the chapter and a group of undergraduate honors students at George Mason University conducted a national survey of state-level maximum security prisons in the United States with the goal of assessing how prison administrators across the county have addressed these and other issues related to the detention of religious extremist inmates (Merola et al., 2011). Though these prisons do not deal specifically with Guantanamo Bay detainees, they do manage other prisoners who have adopted extremist religious beliefs. Additionally, the survey asked about staff training related to religious extremism, the monitoring of inmate communications, and whether or not valuable antiterrorism information could be collected in prisons. Admittedly, this study addresses only a small part of the issues inherent in any proposed relocation of prisoners from Guantanamo Bay or even the incarceration of any future individuals convicted of terrorism. Knowledge accumulation through social science is always incremental in nature and, in some cases, necessary data may even be inaccessible or infeasible to collect. However, the notion of evidence-based counterterrorism can help sharpen our focus on linking research to policy options.

Research Related to Judicial Decision-Making

On the whole, a robust empirical literature exists with respect to the topic of judicial decision-making, particularly at the US Supreme Court level. A variety of competing models have been tested using a wide range of methodologies and data from different levels of the court system (Clayton & Gillman, 1998; Epstein & Knight, 1998; Maltzman, Spriggs, & Wahlbeck, 2000; Segal & Spaeth, 2002; Woodford, 1981). Yet, despite the existence of a robust literature in this area and the fact that questions related to the proper scope of judicial authority have been central to post-9/11 legal debates, there are only a small number of social science articles which evaluate post-9/11 judicial decision-making. First, as mentioned above, quantitative research in this area has examined the question of whether or not judges alter their decisions during times of war (Clark, 2006; Epstein et al., 2005). Though these projects did not focus specifically on understanding post-9/11 alterations in the judiciary, these studies can serve as models for additional literature on judicial decision-making in times of terrorism.

In addition to these studies of judicial voting, another existing article utilizes an experimental methodology to examine post-9/11 judicial decision-making. Generally, few researchers in the field of judicial decision-making employ an experimental methodology, but it is worth highlighting the use of this methodology here. Hagan, Farrales, and Jasso (2008) conduct a factorial experiment to examine how Iraqi judges might adjudicate cases in which American military members are accused of torturing suspected terrorists. In reality, Iraqi judges did not preside over such cases, since crimes committed by American military are adjudicated within the American military justice system. However, the researchers utilized the experimental method to shed light on various aspects of the decision-making of these judges. In fact, the researchers provided evidence that hypothetical sentences became stricter when the individual judge was highly concerned that instances of torture would encourage further violence in Iraq (Hagan et al.). According to the researchers, “the judges who were less fearful of violence were more lenient and accommodating of torture by Coalition forces. The implication is that the less fearful judges were freed by an indeterminate law to advance Coalition goals through lenient punishment of torture” (Hagan et al., p. 605).

One potential benefit of experimental methodologies is that empirical researchers may use experiments of this type to conduct simulated tests in areas where it might be impossible or impractical to collect “real world” data. This is particularly useful in the case of terrorism research, where data may be inaccessible for many reasons. Though not always as reliable as experiments or empirical analyses based upon real world data, laboratory experiments have been utilized in many fields to simulate justice processes of interest. For example, the research conducted by psychologists in the field of juror decision-making provides an example of this (Diamond & Rose, 2005). In lieu of witnessing the deliberations of actual jurors, psychologists have attempted to recreate juror decision-making under laboratory conditions. Certainly, the conditions under which such experiments take place must be carefully monitored in order to represent the actual process as closely as possible. Admittedly, judicial decision-making may be a difficult area in which to utilize experimental methods under most circumstances, due to the difficulty in replicating the training and socialization of judges among experimental participants. However, it is worth highlighting the Hagan et al. study as one of only very few studies of post-9/11 judicial decision-making. Additionally, it is again worth emphasizing the utility of experimental studies more generally in the context of terrorism research, as often these can represent creative solutions by researchers who cannot collect real world data.

Conclusion

Despite substantial expenditures for the purposes of counterterrorism, few social scientific evaluations of counterterror measures have been published (Lum et al., 2006). This is particularly the case with respect to empirical studies of law-related counterterrorism policy. Traditionally, many legal scholars have not utilized the methods of social science (such as surveys, experiments, or large scale data analysis, for example) in their work, so perhaps this scarcity of empirical research merely reflects the larger orientation of the field. Yet, over time, this orientation is changing, as greater numbers of legal scholars pursue joint degree programs or embrace the perspectives of fields like law and society and empirical legal studies. Regardless, it remains the case that the momentum behind publishing doctrinal studies related to law and terrorism has somehow largely not translated into scholarly focus on empirical studies in this area.

The goal of this chapter was to explore the existing empirical legal research related to counterterrorism measures. Though not meant to be an all-encompassing literature review, this chapter surveyed a varied literature related to law and terrorism, finding that only a very small number of authors have actually conducted evaluations of specific post-9/11 legal policies. In fact, the author could only locate a few studies that could be likened to the evidence-based evaluations of policy that take place in other fields. Yet, this should not minimize the importance of other types of studies related to law and terrorism that may be used both independently and as a foundation for building the empirical evidence base further. For example, a comparatively robust empirical literature exists related to public support for the norm of expansive civil liberties during the post-9/11 period. Though not strictly evaluation research, the findings from this literature are fairly comprehensive and may be linked to specific measures in a number of ways. For example, one of the key findings of this literature relates to the impact of information on support for civil liberties. For this reason, it was suggested that researchers might investigate specific measures related to information that could make communities more resilient to terrorism.

Additionally, the author located a small number of empirical studies related to legal elite opinions, an area of research that seems likely to be helpful to those making decisions about counterterrorism policy. After all, legal elites (as well as other elites) possess expertise that can effectively guide policy makers, particularly when the opinions of an expert community are assessed systematically. Finally, some additional empirical studies in the areas of separation of powers and judicial decision-making were discussed. Here, pioneering studies – such as large scale studies of judicial voting in times of war or a wholly experimental study investigating post-9/11 judicial decision-making – were described as examples of cutting edge empirical research related to law and terrorism. Among other reasons, these studies are also noteworthy because their authors embraced methodologies novel to their fields when it would aid their research.

Currently, a discussion of law-related terrorism research in the context of the evidence-based paradigm is somewhat challenging to accomplish, since so few empirical studies exist and even fewer have connected their investigations to specific policy questions or evaluated specific outcomes. Yet, it is for this reason that a survey of the law and terrorism literature from the vantage point of evidence-based counterterrorism is interesting. An important tenet of the evidence-based paradigm is to forge a closer link between researchers and practitioners with the goal of making policy more effective (Pfeffer & Sutton, 2006). This paradigm demands that practitioners account for the findings of scholarly research while developing policy, but it also suggests a bridge whereby researchers can speak to practitioners and have greater influence on policy development (Pfeffer & Sutton, 2006; Rousseau, 2006). In the end, greater attention to creating an empirical evidence base upon which policy makers can draw in times of crisis can only increase the impact of our scholarship.