the United States to Morocco to India, various venues on the internet, several auction settings, shopping malls, various labor markets, and grammar and high schools. In the past two decades, List has expanded his research agenda to explore theoretical and empirical aspects of scaling ideas and policies. Behavioral economics List's research on behavioral economics has focused on testing theories like gift exchange, social preferences, and prospect theory. Traditional tests of these theories relied on recruiting undergraduate students to participate in experiments for a small amount of money. List instead recruited subjects in actual marketplaces to participate in experiments, sometimes unbeknownst to even the subjects. List's field experiments have found that gift exchange is not as powerful a motivator of labor effort as earlier research found, that social preferences are not as pronounced as prior research found, and that the divergence between Willingness to Pay and Willingness to Accept often called the endowment effect, predicted by prospect theory, disappears with market experience. List's recent work in behavioral economics has found that framing can induce increased worker productivity., and has been picked up by several corporations around the world. Environmental economics List has published research on the impact of environmental regulation on economic production and on endangered species. List's research has also focused on testing non-market valuation mechanisms in the field frequently used in contingent valuation and in testing different incentives to promote environmentally friendly technology adoption. He also teaches in Kiel University Research Institute in summer 2017 where he developed ideas on non-market valuation using field experiments. Charitable giving List has also brought social preferences and value of public goods to the marketplace by testing determinants of charitable giving. List has found that a number of the traditional techniques in the philanthropy world are not well understood. For example, the higher the announced seed money the more people give. Also, matching grants increase giving, but it doesn't matter if the match is 1:1 or 3:1. List has also found that giving is easily influenced by incentives that discount the importance of altruism in motivating giving. For example, List has found that beauty and social pressure are important motivators for giving. In an experiment through a solicitation mailed to 300,000 households in Alaska, List found that people are more likely to give because they want to feel good, rather than from pure altruism. Some of his field experimental work on charitable fundraising