Social controls influence the environmental performance of firms and require them to be more accountable for their environmental impacts. These controls include governmental interventions such as mandatory disclosure requirements, regulation and subsidisation, as well as less formal controls such as stakeholder opinion. This thesis examines the relative influence of environmental social controls on the acceptability of capital investment and provides insight into the perceptions of Australian managers concerning capital investment decision-making. An experiment is used to measure the relative influence of the four social control measures. This is supported by a survey to gauge firm size and industry influences and also a range of attributes of the controls on the capital investment decision. Experiment results suggest that the influence of stakeholder opinion on capital investment is very high and mandatory disclosure very low. The survey measured the influence of a range of indicators of each control and also firm size and industry effects. Firm size effects were weak while industry effects were much clearer and more consistent. A comparison of the influence of social control indicators and a range of financial and strategic indicators on the capital investment decision showed that the mainstream indicators had more influence. / Doctor of Philosophy (PhD)