Interest in environmental, social, and governance (ESG) issues is at an all-time high. However, academic research is still relatively nascent, often leading us to apply gut feel on the grounds that ESG is too urgent to wait for peer-reviewed research. This paper highlights how the insights of mainstream economics can be applied to ESG, once we realize that ESG is no different to other investments with long-term financial and social returns. A large literature on corporate finance studies how to value investments; asset pricing explores how the stock market prices risks; welfare economics investigates externalities; optimal contracting considers how to achieve multiple objectives; private benefits analyze manager and investor preferences beyond shareholder value; and agency theory helps ensure that managers pursue shareholder preferences, including nonfinancial preferences. I identify how conventional thinking on ten common ESG myths is overturned when applying the insights of mainstream economics.