There are many different branches of economics which can be applied to the study of addiction. In this lecture I am exploring the application of economic evaluation techniques to inform research and policy debates about treatment policy for tobacco, alcohol and illicit drug use. Initial applications of economics led to estimates of the social burden of different substances in monetary terms. Such figures were used in advocacy for public funding or insurance coverage for treatment. The argument was to suggest that treatment was one policy strategy for reducing these social burdens. Further research focussed on attempting to provide more direct evidence that additional treatment would be socially beneficial. More recently there have been more detailed and technical economic evaluation studies attempting to answer questions about which specific treatments should or should not be supported. Economists would suggest their methodological research and empirical analyses are designed not to dictate policy choices but to “aid” or be a specific part of the policy debate. But some of these economic analyses, especially when linked to regulatory agencies such as the National Institute for Health and Clinical Excellence (NICE) in England can have a profound effect on treatment choices for users and service providers. What are the methodological and ethical challenges of undertaking economic evaluations relevant to addiction treatment policy? I will argue in this lecture that economists can and should contribute to the addiction treatment policy debate. However, economists and others are far from agreement on the best assumptions and methodologies to adopt. The aim of the lecture is to set out some of the major issues illustrated with empirical examples. An objective is to convince the wider addiction community to become more actively involved in critically understanding and contributing to future studies. I hope I can convince the audience that economics is not just about “making money talk” but also about setting out the ethical values of policy choices.