This Masterclass addresses economics and sustainability in the context of global conservation and development challenges. The sessions are structured around the economic causes and solutions for climate, water, and biodiversity, three key areas where economists have produced definitive reports in the past 20 years. At the end of this 3-hour Masterclass, participants will understand the major sources of market and governance failures, the economic “toolkit” of policies and incentives for responding in both lower and higher income settings, and the major bright spots and breakthroughs in the field with a focus on behavioural insights and development economics.  Participants will learn how to think through sustainability challenges and solutions like an economist, and gain confidence linking economic ideas and insights with expertise in data science and other disciplines.