Optimalbesteuerung Bei Alternativen Sozialen Wohlfahrtsfunktionen

Abstract

OPTIMAL TAXATION UNDER ALTERNATIVE SOCIAL WELFARE FUNCTIONS by Christian SEIDL, University of Graz, Austria.

This paper examines optimal taxation in a world with two types of taxpayers (skilled and unskilled) under various social welfare functions (utilitarian, minimization of total sacrifice, RAWLS’ maximin-justice, PARETO-optimum), two behavioural assumptions on the part of the taxpayers (tax-responsive or tax-irresponsive labour-supply, respectively), and two assumptions on the informational status of the tax authorities (perfect and asymmetric information, respectively). We find that tax-irresponsive labour supply under perfect information of the tax authorities does not lead to an equal distribution of post-tax incomes, but reveal tendencies towards negative association between consumption and labour with the exception of maximin-justice which implies positive association between consumption and labour. Under the economically plausible assumption U₁₂<0, skilled individuals are endowed with greater utility under maximin-justice, as compared, e.g., with utilitarianism. The assumption of tax-responsive labour supply under perfect information of the tax authorities does not change these results dramatically. Major new results occur, however, under the assumption of asymmetric information of the tax authorities. In such a world, only solutions satisfying additional constraints, the so-called self-selection constraints, are feasible. These constraints prevent exploitation of taxpayers, because they could retaliate by cheating: they could pretend to be of an other type, thus evading exploitation. These constraints exclude all solutions which would, e.g., assign a smaller utility to skilled individuals than to unskilled ones. In most cases, these constraints demanding true revelation of the taxpayer’s type imply distortive taxation at the margin (and thus inefficiency) for at least one type of taxpayers, whereas perfect Information required lump-sum taxation (and thus efficiency) for both types. The respective optimal tax tariffs are discontinuous under asymmetric information.

Den Teilnehmern am Brixener Symposion, insbesondere den Herren Dr. Georg TILLMANN, Bonn, und Prof. Dr. Wolfgang EICHHORN, Karlsruhe, bin ich für hilfreiche Kritik sehr zu Dank verpflichtet. Frühere Fassungen dieses Referates wurden an den Universitäten Graz, Heidelberg und München vorgetragen. Den Seminarteilnehmern sei für die Diskussion herzlich gedankt.