A number of labor markets and student placement systems can be modeled as many-to-one matching markets. We analyze the scope for manipulation in many-to-one matching markets under the student-optimal stable mechanism when the number of participants is large. Under some regularity conditions, we show that the fraction of participants with incentives to misrepresent their preferences when others are truthful approaches zero as the market becomes large. With an additional condition, truthful reporting by every participant is an approximate equilibrium under the student-optimal stable mechanism in large markets. (JEL C78)

Empirical and experimental evidence suggests different levels of sophistication among families in the Boston Public School student assignment plan. We analyze the preference revelation game induced by the Boston mechanism with sincere players who report their true preferences and sophisticated players who play a best response. We characterize the set of Nash equilibrium outcomes as the set of stable matchings of a modified economy, where sincere students lose priority to sophisticated students. Any sophisticated student weakly prefers her assignment under the Pareto-dominant Nash equilibrium of the Boston mechanism to her assignment under the recently adopted student-optimal stable mechanism. (JEL D82, I21)

Stocks are short-sale constrained when there is a strong demand to sell short and a limited supply of shares to borrow. Using data on both short interest (a proxy for demand) and institutional ownership (a proxy for supply) we find that constrained stocks underperform during the period 1988–2002 by a significant 215 basis points per month on an equally weighted basis, although by only an insignificant 39 basis points per month on a value-weighted basis. For the overwhelming majority of stocks, short interest and institutional ownership levels make short selling constraints unlikely.

Conventional value-added models (VAMs) compare average test scores across schools after regression-adjusting for students’ demographic characteristics and previous scores. This article tests for VAM bias using a procedure that asks whether VAM estimates accurately predict the achievement consequences of random assignment to specific schools. Test results from admissions lotteries in Boston suggest conventional VAM estimates are biased, a finding that motivates the development of a hierarchical model describing the joint distribution of school value-added, bias, and lottery compliance. We use this model to assess the substantive importance of bias in conventional VAM estimates and to construct hybrid value-added estimates that optimally combine ordinary least squares and lottery-based estimates of VAM parameters. The hybrid estimation strategy provides a general recipe for combining nonexperimental and quasi-experimental estimates. While still biased, hybrid school value-added estimates have lower mean squared error than conventional VAM estimates. Simulations calibrated to the Boston data show that, bias notwithstanding, policy decisions based on conventional VAMs that control for lagged achievement are likely to generate substantial achievement gains. Hybrid estimates that incorporate lotteries yield further gains.

This paper uses data on all house transactions in Massachusetts over the last 20 years to show that houses sold after foreclosure, or close in time to the death or bankruptcy of a seller, are sold at lower prices than other houses. Foreclosure discounts are on average at 27 percent of the value of a house. Moreover, foreclosures that take place within small local geographies of a house lower the price at which it is sold. Our preferred estimate is that a foreclosure at a distance of 0.05 miles lowers the price of a house by about 1 percent. JEL: D14, R31

There are substantial differences between open-source projects and traditional innovative efforts in private firms. Private firms usually pay their workers, direct and manage their efforts, and control the output and intellectual property created. In an open-source project, however, a body of original material is made publicly available for others to use, under certain conditions. Contributions to open-source projects are made by a diverse array of individual contributors, and for-profit corporations, who must often agree to make enhancements to the original material widely available for nominal cost. This paper empirically examines the dynamics of contributions to open-source software projects. We show that the share of corporate contributions in a sample of approximately 100 open-source projects between 2001 and 2004 is greater in larger and growing projects.

Many schools in large urban districts have more applicants than seats. Centralized school assignment algorithms ration seats at over‐subscribed schools using randomly assigned lottery numbers, non‐lottery tie‐breakers like test scores, or both. The New York City public high school match illustrates the latter, using test scores and other criteria to rank applicants at the city's screened schools, combined with lottery tie‐breaking at the rest. We show how to identify causal effects of school attendance in such settings. Our approach generalizes regression discontinuity methods to allow for multiple treatments and multiple running variables, some of which are randomly assigned. The key to this generalization is a local propensity score that quantifies the school assignment probabilities induced by lottery and non‐lottery tie‐breakers. The utility of the local propensity score is demonstrated in an assessment of the predictive value of New York City's school report cards. Schools that earn the highest report card grade indeed improve SAT math scores and increase graduation rates, though by much less than OLS estimates suggest. Selection bias in OLS estimates of grade effects is egregious for screened schools.

We use admissions lotteries to estimate the effects of attendance at Boston's charter high schools on college preparation, college attendance, and college choice. Charter attendance increases pass rates on the high-stakes exam required for high school graduation in Massachusetts, with especially large effects on the likelihood of qualifying for a state-sponsored college scholarship. Charter attendance has little effect on the likelihood of taking the SAT, but shifts the distribution of scores rightward, moving students into higher quartiles of the state SAT score distribution. Boston's charter high schools also increase the likelihood of taking an Advanced Placement (AP) exam, the number of AP exams taken, and scores on AP Calculus tests. Finally, charter attendance induces a substantial shift from two-to four-year institutions, though the effect on overall college enrollment is modest. The increase in four-year enrollment is concentrated among four-year public institutions in Massachusetts. The large gains generated by Boston's charter high schools are unlikely to be generated by changes in peer composition or other peer effects.

We measure the capitalization of housing market externalities into residential housing values by studying the unanticipated elimination of stringent rent controls in Cambridge, Massachusetts, in 1995. Pooling data on the universe of assessed values and transacted prices of Cambridge residential properties between 1988 and 2005, we find that rent decontrol generated substantial, robust price appreciation at decontrolled units and nearby never-controlled units, accounting for a quarter of the $7.8 billion in Cambridge residential property appreciation during this period. The majority of this contribution stems from induced appreciation of never-controlled properties. Residential investment explains only a small fraction of the total.