We propose a new organizing scheme for classifying types of experiments. In addition to the standard categories of laboratory and field experiments, we suggest a new category: “extra-laboratory experiments.” These are experiments that have the same spirit as laboratory experiments, but are...

In this article we explore the issues that surround within-subject and between-subject designs. We describe experiments in economics and in psychology that make comparisons using either of these designs (or both) that sometimes yield the same results and sometimes do not. The overall goal is to...

Are men more willing to take financial risks than women? The answer to this question has immediate relevance for many economic issues. We assemble the data from 15 sets of experiments with one simple underlying investment game. Most of these experiments were not designed to investigate gender...

Economists and psychologists have developed a variety of experimental methodologies to elicit and assess individual risk attitudes. Choosing which to utilize, however, is largely dependent on the question one wants to answer, as well as the characteristics of the sample population. The goal of...

We study the following basic intuition: when faced with a decision how to split their investment between a risky lottery and an asset with a fixed return, people increase the proportion invested in the risky option the more they like the lottery. We find counter-examples to this, and in fact we...

Can incentives be effective in encouraging the development of good habits? We investigate the post-intervention effects of paying people to attend a gym a number of times during one month. In two studies we find marked attendance increases after the intervention relative to attendance changes...

We report the results of a randomized controlled trial testing whether incentivizing physical exercise improves the academic performance of college students. As expected, the intervention increases physical activity. The main result is that it generates a strong and significant improvement in...

The standard procedure in experimental economics maintains anonymity among laboratory participants. Yet, many field interactions are conducted with neither complete anonymity nor complete familiarity. When we are involved in interactive situations in the field, we usually have some clues...