Book excerpt: This dissertation is the combination of three distinct papers on Behavioral Economics and Market Design. In the first paper, I theoretically and empirically analyze consumer and producer behavior in a relatively new auction format, in which each bid costs a small amount and must be a small increment above the current high bid. I describe the set of equilibrium hazard functions over winning bids and identify a unique function with desirable conditions. Then, I examine bidder behavior using two datasets of 166,000 auctions and 13 million individual bids, captured with a real-time collection algorithm from a company called Swoopo. I find that players overbid significantly in aggregate, yielding average revenues of 150% of the good's value and generating profits of €18 million over four years. While the empirical hazard rate is close to the predicted hazard rate at the beginning of the auction, it deviates as the auction progresses, matching the predictions of my model when agents exhibit a sunk cost fallacy. I show that players' expected losses are mitigated by experience. Finally, I estimate both the current and optimal supply rules for Swoopo using high frequency data, demonstrating that the company achieves 98.6% of potential profit. The analysis suggests that over-supplying auctions in order to attract a larger userbase is costly in the short run, creating a large structural barrier to entrants. I support this conclusion using auction-level data from five competitors, which establishes that entrants collect relatively small or negative daily profits. The second paper (joint with Scott Nicholson) addresses the impact of making multiple previous choices on decision making, which we call "choice fatigue." We exploit a natural experiment in which different voters in San Diego County are presented with the same contest decision at different points on the ballot, providing variation in the number of previous decisions made by the voters. We find that increasing the position of a contest on the ballot increases the tendency to abstain and to rely on decision shortcuts, such as voting for the status-quo or the first candidate listed in a contest. Our estimates suggest that if an average contest was placed at the top of the ballot (when voters are "fresh"), abstentions would decrease by 10%, the percentage of "no" votes on propositions (a vote for the status-quo) would fall by 2.9 percentage points, and the percentage of votes for the first candidate would fall by .5 percentage points. Interestingly, if this occurred, our results suggests that 22 (6.25%) of the 352 propositions in our dataset would have passed rather than failed. Implications of the results range from the dissemination of information by firms and policy makers to the design of electoral institutions and the strategic use of ballot propositions. The third paper (joint with Jesse Cuhna) paper presents evidence from a field experiment on the impact of inter-group competition on intra-group contributions to a public good. We sent political solicitations to potential congressional campaign donors that contained either reference information about the past donations of those in the same party (cooperative treatment), those in the competing party (competition treatment), or no information (the control group). The donation rate in the competitive and cooperative treatment groups was 85% and 42% above that in the control, respectively. Both treatments contained a monetary reference point, which influenced the distribution of donations. While the cooperative treatment induced more contributions concentrated near the mentioned reference point, the competitive treatment induced more contributions at nearly twice the level of the given reference point, leading to a higher total contributed amount. This suggests that both cooperative and "pro-social" motives can drive higher contribution rates and total contributions, but the elicitation of competitive behavior can be more profitable in certain fundraising situations.