Since the 1980s, there has been explosive growth in the use of experimental methods in economics, leading to exciting developments in economic theory and policy. Despite this, the status of experimental economics remains controversial. In Experimental Economics, the authors draw on their...

One lingering puzzle is why voluntary contributions to public goods decline over time in experimental and real-world settings. We show that the decline of cooperation is driven by individual preferences for imperfect conditional cooperation. Many people's desire to contribute less than others,...