Nudging consists of changing how alternatives are presented in ways designed to help choosers select what they say they would ideally want. Substantial empirical evidence shows that nudges can significantly—and sometimes substantially—modify behaviors. Yet much remains mysterious about nudging, especially with regard to heterogeneous effects and behavioral welfare economics. How is it possible to create effective choice architectures when not everyone should be nudged the same way? This grant funds a series of experiments by Eric Johnson of Columbia University. He has devised a series of experiments about what he calls “smart nudges.” In contrast to the one-size-fits-all approach, these take into account how individuals differ. One idea is to set different defaults for different people depending on their background characteristics. Another technique, called “preference checklists,” presents a prospective decision-maker with a list of criteria that other people sometimes take into account when considering similar choices. Checking off the criteria that the decision-maker thinks should apply in this case is a way of bringing to mind factors that might otherwise be forgotten or ignored. Johnson’s hypothesis is that choice architectures that incorporate smart defaults and preference checklists will be welfare-enhancing compared to traditional one-size-fits-all nudges. Grant funds support the fielding and analysis of these experiments, and the publication of two papers on the results.