Five hundred and thirty nine psychology and economics majors took part in a tax compliance study investigating the influence of detection rates (within subjects); and the between subject variables of framing effects (loss aversion); instructions to behave instrumentally (or not), and individual differences (major degree undertaken and gender) on the amount of income declared. Respondents systematically declared more as detection rates rose but when considering the effects for framing or for instrumental instruction the results were mixed. However the individual difference measures were crucial factors in the interpretation of the results. Economists declared significantly less income, were significantly influenced by framing effects and in a qualitative analysis were less co-operative and less concerned with the morality of tax (non)compliance compared to psychologists. When the general linear analysis was repeated for males and females separately it was clear that males declared significantly less when tax was framed as a loss. The research method employed is discussed and suggestions are made for further research which can untangle the influence of gender and degree choice and address the question of the appropriate level of 'realism' in the research design.