Models, theories and method

Abstract

Consider an Economics student presented with the following mathematical relationships:

$$x = \alpha z + \beta $$

((1.1))

$$q = \bar q$$

((1.2))

$$z = x + y$$

((1.3))

$$w = x + q$$

((1.4))

$$w = z$$

((1.5))

and suppose he or she is told that equations (1.1)–(1.5) imply:

$$\frac{{{{\text{d}}_z}}}{{{{\text{d}}_{\bar q}}}} = \frac{1}{{1 - \alpha }}(\alpha \ne 1)$$

((1.6))