Knowledge that Transforms

We introduce a framework of matching with flexible allotments that can be used to model firms with cross-division hiring restrictions. Our framework also allows us to nest some prior models of matching with distributional constraints. Building upon our recent work on observable substitutability, we show that multi-division choice functions with flexible allotments enable stable and strategy-proof matching; these results illustrate the value of clearly mapping when stable and strategy-proof matching is possible.

Since the early 1990s, recoveries from recessions in the US have been plagued by weak employment growth. One possible explanation for these "jobless" recoveries is rooted in technological change: middle-skill jobs, often involving routine tasks, are lost during recessions, and the displaced workers take time to transition into other jobs (Jaimovich and Siu, 2014). But technological replacement of middle-skill workers is not unique to the US – it also takes place in other developed countries (Goos, Manning, and Salomons, 2014). So if jobless recoveries in the US are due to technology, we might expect to also see them elsewhere in the developed world. We test this possibility using data on recoveries from 71 recessions in 28 industries and 17 countries from 1970-2011. We find that though GDP recovered more slowly after recent recessions, employment did not. Industries that used more routine tasks, and those more exposed to robotization, did not recently experience slower employment recoveries. Finally, middle-skill employment did not recover more slowly after recent recessions, and this pattern was no different in routine-intensive industries. Taken together, this evidence suggests that technology is not causing jobless recoveries in developed countries outside the US.

Is coachability a usable concept for startups? Using a dataset on high-growth startups in a prominent university incubator, we show that firm characteristics do predict which firms are likely to follow advice but that these “coachable” firms are not more likely to achieve positive outcomes. The reason is that advice may be rejected either because the firm is stubborn and uncoachable, or because the firm possesses capabilities related to the advice which is hard for outsiders to observe.

Although school choice programs are common, we know little about the underlying decision-making processes. In this study, we randomly assigned 900 junior high schools in Ghana, a country with universal secondary school choice, to 1 of 3 treatment arms: (1) information to students, (2) information to students and guardians, and (3) control group. We observe changes in beliefs, behaviors, and the decision maker's identity through a survey of guardians. Our intervention increased the likelihood that guardians were involved with and informed about the school selection process. Moreover, specifically targeting guardians led to significantly larger changes for most outcomes.

Most approaches to entrepreneurship assume that entrepreneurial control over their inventions is critical for success and, in turn, for incentives. Such control is usually supported by regulations that protect intellectual property including patents, copyrights, and trade secrets. Each give the entrepreneurs control over who can appropriate value from their activities. However, we note that another, distinct path exists for appropriation by entrepreneurs' execution. Execution forgoes the formal protection from control instead of a more rapid approach to market in the pursuit of capabilities that will allow entrepreneurs to compete with others in the future rather than block their activities per se. We characterize the conditions under which one path is preferred to another and present evidence from university startups delineating the tradeoffs at the heart of our theoretical approach.

This paper provides a snapshot of undergraduate research at top 30 liberal arts institutions and top 30 national universities (based on U.S. News and World Report rankings, 2017). This description provides a broader perspective than exists in the literature as we identify departmental motivations for providing undergraduate research opportunities despite the lack of mandates. We also document the extent to which a variety of forms of undergraduate research occur (programmatically and by student numbers). Also included are descriptions of innovative approaches to promoting undergraduate research in light of constraints and methods for creating a culture conducive to undergraduate research.

Successful platforms attract not just many users, but also those of the right kind. 'The right kind of user' is one who can either be directly monetized or who differentially attracts other valuable users. Bonacich centrality on the network of user sorting with direct value of monetization captures this feedback loop and thus characterizes the value of user characteristics. We use this value to determine optimal steady-state platform design and reliable means for platforms to reach such a steady state. We apply these results respectively to explain the dynamic growth strategy of social networks and urban development policies of cities.

Many school and college admission systems use centralized mechanisms to allocate seats based on applicant preferences and school priorities. When tie-breaking uses non-randomly assigned criteria like distance or a test score, applicants with the same preferences and priorities are not directly comparable. The non-lottery setting does generate a kind of local random assignment that opens the door to regression discontinuity designs. This paper introduces a hybrid RD/propensity score empirical strategy that exploits quasi-experiments embedded in serial dictatorship, a mechanism widely used for college and selective K-12 school admissions. We use our approach to estimate achievement effects of Chicago's exam schools.

Aggregate real wages exhibit less procyclicality than most macroeconomic models predict. We use 35 years of Current Population Survey data to confirm that the puzzling behavior of wages largely owes to changes in the composition of the employed over the business cycle. This composition effect relates to changes in both the number and the relative wage levels of those entering and exiting. The changing gap in wages of entrants and exiters is especially important for the unemployed. A large part of this wage gap is due to differences in average Mincer residuals between entrants and exiters.

In an earlier work (Kamada and Kojima 2015), we introduced “matching with constraints,” a two-sided matching problem in which the market is subject to feasibility constraints. That paper proposed and analyzed a possible solution to this problem and discussed various real-market applications of our results. The present paper reorganizes some of the findings from our more recent effort, based on Kamada and Kojima (2016a, b).