Commitment is typically modelled by assigning to one of the players the ability to take an initial binding action. The weakness of this approach is that the fundamental question of who has the opportunity to commit cannot be addressed, as it is assumed. This paper presents a framework in which commitment power arises endogenously from the fundamentals of the model. We construct a finite dynamic game in which players are given the option to change their minds as often as they wish, but pay a switching cost if they do so. We show that for games with two players and two actions there is a unique subgame-perfect equilibrium with a simple structure. This equilibrium is independent of the order and timing of moves and is robust to other protocol specifications. Moreover, despite the perfect information nature of the model and the costly switches, strategic delays may arise in equilibrium. The flexibility of the model allows us to apply it to various environments. In particular, we study an entry deterrence situation. Its equilibrium is intuitive and illustrative of how commitment power is endogenously determined.

This paper investigates the effects of mandatory seat belt laws on driver behavior and traffic fatalities. Using a unique panel data set on seat belt usage in all U.S. jurisdictions, we analyze how such laws, by influencing seat belt use, affect the incidence of traffic fatalities. Allowing for the endogeneity of seat belt usage, we find that such usage decreases overall traffic fatalities. The magnitude of this effect, however, is significantly smaller than the estimate used by the National Highway Traffic Safety Administration. In addition, we do not find significant support for the compensating-behavior theory, which suggests that seat belt use also has an indirect adverse effect on fatalities by encouraging careless driving. Finally, we identify factors, especially the type of enforcement used, that make seat belt laws more effective in increasing seat belt usage.

We develop a structural econometric model to estimate risk preferences from data on deductible choices in auto insurance contracts. We account for adverse selection by modeling unobserved heterogeneity in both risk (claim rate) and risk aversion. We find large and skewed heterogeneity in risk attitudes. In addition, women are more risk averse than men, risk aversion exhibits a U-shape with respect to age, and proxies for income and wealth are positively associated with absolute risk aversion. Finally, unobserved heterogeneity in risk aversion is greater than that of risk, and, as we illustrate, has important implications for insurance pricing.

We study one benefit to firms of selling subscriptions: the prospect that consumers will continue to pay for subscriptions they no longer value. We use comprehensive data from a large payment card network to document that months during which cards are replaced, when active renewal is required, are associated with much higher rates of cancellation. Using two stylized models of consumer inertia—driven by inattention or switching costs—we estimate that these cancellation frictions roughly double seller revenues on average, holding fixed initial subscribers. We use the estimated models to explore the impact of possible regulatory remedies.

Much of the extensive empirical literature on insurance markets has focused on whether adverse selection can be detected. Once detected, however, there has been little attempt to quantify its welfare cost or to assess whether and what potential government interventions may reduce these costs. To do so, we develop a model of annuity contract choice and estimate it using data from the U.K. annuity market. The model allows for private information about mortality risk as well as heterogeneity in preferences over different contract options. We focus on the choice of length of guarantee among individuals who are required to buy annuities. The results suggest that asymmetric information along the guarantee margin reduces welfare relative to a first-best symmetric information benchmark by about £127 million per year or about 2 percent of annuitized wealth. We also find that by requiring that individuals choose the longest guarantee period allowed, mandates could achieve the first-best allocation. However, we estimate that other mandated guarantee lengths would have detrimental effects on welfare. Since determining the optimal mandate is empirically difficult, our findings suggest that achieving welfare gains through mandatory social insurance may be harder in practice than simple theory may suggest.

We present new evidence on consumer liquidity constraints and the credit market conditions that might give rise to them. We analyze unique data from a large auto sales company serving the subprime market. Short-term liquidity appears to be a key driver of consumer behavior. Demand increases sharply during tax rebate season and purchases are highly sensitive to down-payment requirements. Lenders also face substantial informational problems. Default rates rise significantly with loan size, providing a rationale for loan caps, and higher-risk borrowers demand larger loans. This adverse selection is mitigated, however, by risk-based pricing.

We study the introduction of a noninvasive prenatal screening—cell-free DNA (cfDNA) screening—which is used to target a more costly invasive test that elevates miscarriage risk. Using Swedish administrative data, we document that coverage of cfDNA substantially increases cfDNA screening and reduces invasive testing. We develop and estimate a stylized model of prenatal choices and find that narrow targeting of cfDNA coverage can improve outcomes and reduce costs, while broader coverage also improves outcomes but with increased costs. These findings point to the potential gains from well-designed targeting of screening but at the same time highlight the importance of the targeting design.

We estimate the sensitivity of Internet retail purchasing to sales taxes using eBay data. Our first approach exploits the fact that a seller's location—and therefore the applicable tax rate—is revealed only after a buyer has expressed interest in an item. We document how adverse tax “surprises” reduce the likelihood of purchase and shift subsequent purchases toward out-of-state sellers. We then use more aggregated data to estimate that every one percentage point increase in a state's sales tax increases online purchases by state residents by almost 2 percent, while decreasing their online purchases from state retailers by 3–4 percent.

We estimate the economic surplus created by the Medicare Advantage program under its reformed competitive bidding rules. We use data on the universe of Medicare beneficiaries and develop a model of plan bidding that accounts for both market power and risk selection. We estimate that the Medicare Advantage program generates substantial surplus to participants (of $217 per enrollee-month), but that approximately two-thirds of this surplus is captured by insurers. We use the model to evaluate the impact of possible program changes, including changes that could increase competition and lead to lower profits and higher consumer surplus without raising taxpayer costs.

Auctions were very popular in the early days of internet commerce, but today online sellers mostly use posted prices. We model the choice between auctions and posted prices as a trade-off between competitive price discovery and convenience. Evidence from eBay fits the theory. We then show that the decline in auctions was not driven by compositional shifts in seller experience or items sold, but by changing seller incentives. We estimate the demand facing sellers and document falling sale probabilities and falling relative demand for auctions. Both favor posted prices; our estimates suggest the latter is more important for the auction decline. Survey evidence provides further support.