Recently some authors have revived Max Weber's discussion of the connection between religion and economic growth (see e.g. Barro and Macleary, 2003 and Guiso, Sapienza and Zingales, 2002). Most of this literature examines the connection between religion and economic outcomes on an aggregate or cross-country level making it difficult to discern the channels by which religion affects economic outcomes and to address endogeneity issues. This project will examine the relationship between religion and economic attitudes at the level of individuals. In particular, the study will focus on the role of religious rites in making credible religiosity and deeper personal traits. Using data from the Central Bazaar in Tehran, we will examine the extent to which shop owners' success is affected by the degree of religiosity they display. We will analyze believers and non-believers. Expressions that are more costly to non-believers are assumed to be more credible. Through the survey we will also attempt to establish whether 'credibility signalling' effects sales or whether cheaper credit has a greater effect. Finally, we intend to repeat the survey on two occasions to determine whether religious rites are just a signalling device or whether they have any actual effect on values (so-called hardwiring).