How have universities managed to survive and evolve over almost 1,000 years to become wildly heterogeneous, unusually fractious, multi-product, non-profit entities? Universities began as teachers’ guilds, and they still give faculty a remarkable degree of autonomy. That structure attracts and empowers intellectuals, who are selected in part on their taste for knowledge, and those entrepreneurs and philanthropists have enabled universities to morph in ways that firms rarely do. Intellectual autonomy can also explain why universities are so often at odds with legal authorities and why faculty fight so often with each other and with their bosses. This essay presents a model of university organization and sketches the evolution of the university’s products and conflicts over the last 900 years. We also discuss the social value of university education. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Edward L Glaeser of Harvard University reviews “Chicago before the Fire: An Economic History” by Louis P. Cain The Econlit abstract of this book begins: “Examines the economic and business history of Chicago before the Great Fire of 1870, focusing on how the city's early growth and development determined its rise as the Midwest's dominant city.”

What determines whether and how regulations are reformed? We use a newly constructed data set of 3,590 successful and failed regulatory reforms in 189 countries, between 2005 and 2022, to address this question. We document that regulations have become more business friendly in some regulatory domains but not others. We also show that regulations are more business friendly in richer than in poorer countries, and that holding initial regulatory levels constant, richer countries also reform more. We present a model in which the successful passage of reforms is shaped by the number of veto points in the approval process, the social returns to reform, and the cost of compensating losers from reform, and then test it using our new data set. We find that richer countries have both higher reform attempt and success rates, but less impact of individual reforms on regulation than poorer countries. These findings are consistent with the model if richer countries are better at reform, perhaps because they can compensate losers more efficiently. Across the world, reform attempt rates are strongly correlated with reform success rates but not with reform impact levels. Within countries, a higher share of technological reform attempts is successful, compared to administrative or legal reforms, consistent with the importance of veto points. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Public capacity complements urban density because externalities abound in cities and urban scale makes it possible to share infrastructure that needs to be managed. Yet, urban governments face limitations that are not experienced by private sector entities. A city cannot just stop policing if it decides it is bad at policing. Typically, public compensation and personnel policies are highly regulated either by law or by union contracts. City governments do, however, have one great advantage over private entities: a greater ability to learn from their peers. City governments do similar things throughout the world, while companies frequently specialize. Private companies have strong incentives to hide the trade secrets that make them more productive, cities do not. As individual cities do not have an incentive to make it easier for other governments to learn from them, multinational entities like the Asian Development Bank and the World Bank could enable that learning. Since climate-change-related crises are relatively rare events, city-to-city learning seems particularly important for adapting to climate change.

This JAMA Forum discusses the recent budget cuts to National Institutes of Health (NIH), the effects of these cuts on scientific research and health of individuals in the US, and the prospects for changes to Trump administration policies.

Housing prices across much of America have hit historic highs, while less housing is being built. If the US housing stock had expanded at the same rate from 2000-2020 as it did from 1980-2000, there would be 15 million more housing units. This paper analyzes the decline of America's new housing supply, focusing on large Sunbelt markets such as Atlanta, Dallas, Miami, and Phoenix that were once building superstars. New housing growth rates have decreased and converged across these and many other metro areas, and prices have risen most where new supply has fallen the most. A model illustrates that structural estimation of long-term supply elasticity is difficult because variables that make places more attractive are likely to change neighborhood composition, which itself is likely to influence permitting. Our framework also suggests that as barriers to building become more important and heterogeneous across place, the positive connection between building and home prices and the negative connection between building and density will both attenuate. We document both of these trends throughout America's housing markets. In the Sunbelt, these changes manifest as substantially less building in lower-density census tracts with higher home prices. America's suburban frontier appears to be closing.

Do more populous neighborhoods grow less quickly than less populous areas? Is local housing price growth associated with initial population density? The Longitudinal Tract Data Base’s (LTDB) panel of Census tracts is the standard tool for measuring neighborhood change. The LTDB is based on 2010 Census tract boundaries, and Census tracts are partially designed so that they have a similar level of population. In this paper, we show that defining neighborhoods to equalize ex post population levels can significantly impact estimated coefficients in regressions in which population changes are regressed on initial population levels or with variables that are correlated with initial population levels. Most obviously, if neighborhood populations are ex post equalized, then a regression of population change on initial population must yield a coefficient of -1. We address this challenge by offering five alternative panels of tracts using 1970, 1980 and 1990 boundaries, which can be thought of as ‘reverse LTDBs’. The significant mean reversion of both population and housing units that appear in the LTDB before 2000 either dramatically ameliorates or reverses using the reverse LTDB. Comparing the LTDB with the reverse LTDB also finds that using tracts based on ex post borders also can influence estimated growth relationships where other tract-level attributes such as house price are correlated with initial population levels. This does not imply that using ex ante borders always is superior; earlier borders almost always means fewer observations, especially in rapidly growing areas. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

We analyze changes in pedestrian behavior over a 30-y period in four urban public spaces located in New York, Boston, and Philadelphia. Building on William Whyte's observational work, which involved manual video analysis of pedestrian behaviors, we employ computer vision and deep learning techniques to examine video footage from 1979-80 and 2008-10. Our analysis measures changes in walking speed, lingering behavior, group sizes, and group formation. We find that the average walking speed has increased by 15%, while the time spent lingering in these spaces has halved across all locations. Although the percentage of pedestrians walking alone remained relatively stable (from 67% to 68%), the frequency of group encounters declined, indicating fewer interactions in public spaces. This shift suggests that urban residents are using streets as thoroughfares rather than as social spaces, which has important implications for the role of public spaces in fostering social engagement.

In the World Bank Enterprise Survey, the share of entrepreneurs who are women first rises and then falls with national income, while female labor force participation has the opposite U-shaped pattern. We present a model in which gender-based disadvantages, such as discrimination and household obligations, deter firm formation in poor countries and complex firm formation in rich countries. In middle-income countries, high returns to entrepreneurship offset gender-based costs, and firms remain simple. We document that female-owned firms are smaller and simpler. Larger firms are more productive. The female entrepreneurship rate is associated with female education, weak kinship ties, and Buddhism.

We measure the level and growth of educational segregation in US workplaces from 2000 to 2020. US workplaces showed an educational segregation, measured by the degree to which the establishment has mostly workers of similar education levels, that is comparable to racial residential segregation in a typical metro area. Workplace isolation was particularly high for young and male workers without college degrees. The isolation of noncollege workers is increasing over time. In a companion work, we document that the career trajectories of noncollege workers were diminished when they were in establishments in 2000 that contained fewer college-educated workers.

Are developing-world cities engines of opportunities for low-wage earners? In this study, we track a cohort of young low-income workers in Brazil for thirteen years to explore the contribution of factors such as industrial structure and skill segregation on upward income mobility. We find that cities in the south of Brazil are more effective engines of upward mobility than cities in the north and that these differences appear to be primarily related to the exposure of unskilled workers to skilled co-workers, which in turn reflects industry composition and complexity. Our results suggest that the positive effects of urbanization depend on the skilled and unskilled working together, a form of integration that is more prevalent in the cities of southern Brazil than in northern cities. This segregation, which can decline with specialization and the division of labor, may hinder the ability of Brazil's northern cities to offer more opportunities for escaping poverty.

We document a Kuznets curve for construction productivity in 20th-century America. Homes built per construction worker remained stagnant between 1900 and 1940, boomed after World War II, and then plummeted after 1970. The productivity boom from 1940 to 1970 shows that nothing makes technological progress inherently impossible in construction. What stopped it? We present a model in which local land-use controls limit the size of building projects. This constraint reduces the equilibrium size of construction companies, reducing both scale economies and incentives to invest in innovation. Our model shows that, in a competitive industry, such inefficient reductions in firm size and technology investment are a distinctive consequence of restrictive project regulation, while classic regulatory barriers to entry increase firm size. The model is consistent with an extensive series of key facts about the nature of the construction sector. The post-1970 productivity decline coincides with increases in our best proxies for land-use regulation. The size of development projects is small today and has declined over time. The size of construction firms is also quite small, especially relative to other goods-producing firms, and smaller builders are less productive. Areas with stricter land use regulation have particularly small and unproductive construction establishments. Patenting activity in construction stagnated and diverged from other sectors. A back-of-the-envelope calculation indicates that, if half of the observed link between establishment size and productivity is causal, America’s residential construction firms would be approximately 60 percent more productive if their size distribution matched that of manufacturing. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Equally educated people are healthier if they live in more educated places.Every 10 percent point increase in an area's share of adults with a college degree is associated with a decline in all-cause mortality by 7%, controlling for individual education, demographics, and area characteristics.Area human capital is also associated with lower disease prevalence and improvements in selfreported health.The association between area education and health increased greatly between 1990 and 2010.Spatial sorting does not drive these externalities; there is little evidence that sicker people move disproportionately into less educated areas.Differences in health-related amenities, ranging from hospital quality to pollution, explain no more than 17% of the area human capital spillovers on health.Over half of the correlation between area human capital and health is a result of the correlation between area human capital and smoking and obesity.More educated areas have stricter regulations regarding smoking and more negative beliefs about smoking.These have translated over time into a population that smokes noticeably less and that is less obese, leading to increasing divergence in health outcomes by area education.

Boston's high housing costs reflect a historic failure to build enough units to satisfy demand.Interest rates and construction costs have risen recently, and the flow of new market-rate residential housing projects has slowed.To spur more construction, the City of Boston is considering various policy options.Our committee was asked by Boston Mayor Michelle Wu to assess the market impacts of one of these options: real estate tax abatements.This report presents our analysis of the likely effects on the number of units constructed and the costs to taxpayers of various tax abatement alternatives.We do not recommend which policy, if any, the city should pursue; Boston officials are better positioned to assess whether the benefits of these policies warrant the costs to taxpayers.

Cities provide access to stores, public amenities and other people, but that access may provide less benefit for the lower-income and younger urbanites who lack money and means of easy mobility. Using detailed GPS location data, we measure the urban mobility and experienced racial and economic isolation of the young and the disadvantaged. We find that students in major metropolitan areas experience more racial and income isolation, spend more time at home, stay closer to home when they do leave, and visit fewer restaurants and retail establishments than adults. Looking across levels of income, students from higher-income families visit more amenities, spend more time outside of the home, and explore more unique locations than low-income students. Combining a number of measures into an index of urban mobility, we find that, conditional on income, urban mobility is positively correlated with home neighborhood characteristics such as distance from the urban core, car ownership and social capital.

Research SummaryWe evaluate a pilot in an Inspections Department to explore the returns to a pair of algorithms that varied in their sophistication. We find that both algorithms provided substantial prediction gains, suggesting that even simple data may be helpful. However, these gains did not result in improved decisions. Inspectors often used their decision authority to override algorithmic recommendations, partly to consider other organizational objectives without improving outcomes. Interviews with 55 departments find that while some ran pilots seeking to prioritize inspections using data, all provided considerable decision authority to inspectors. These findings suggest that for algorithms to improve managerial decisions, organizations must consider both the returns to algorithms in the context and how decision authority is managed.Managerial SummaryWe evaluate a pilot in an Inspections Department to explore the returns to algorithms on decisions. We find that the greatest gains in this context come from integrating data into the decision process in the form of simple heuristics, rather than from increasing algorithmic sophistication or additional data. We also find that these improvements in prediction do not fully translate into improved decisions. Decision-makers were less likely to follow data-driven recommendations, partly in consideration of other organizational objectives, but without substantially improving on them overall. These findings suggest that organizations should consider the returns to technical sophistication in each context, and that the design and management of decision authority can be a key choice that impacts the value organizations can capture from using predictive analytics.

Americans travel 7 to 9 miles on average for shopping and recreational activities, which is far longer than the 15-minute (walking) city advocated by ecologically-oriented urban planners. This paper provides a comprehensive analysis of local trip behavior in US cities using GPS data on individual trips from 40 million mobile devices. We define local usage as the share of trips made within 15-minutes walking distance from home, and find that the median US city resident makes only 12% of their daily trips within such a short distance. We find that differences in access to local services can explain eighty percent of the variation in 15-minute usage across metropolitan areas and 74 percent of the variation in usage within metropolitan areas. Differences in historic zoning permissiveness within New York suggest a causal link between access and usage, and that less restrictive zoning rules, such as permitting more mixed-use development, would lead to shorter travel times. Finally, we document a strong correlation between local usage and experienced segregation for poorer, but not richer, urbanites, which suggests that 15-minute cities may also exacerbate the social isolation of marginalized communities.