National Bureau of Economic Research

Roughly 1 billion people live more than two kilometers from an all-season road, primarily in emerging-market and developing economies (EMDEs), where limited access to paved roads constrains growth and development. Despite a critical investment shortfall, in the absence of readily accessible data on historical returns, private investors remain reluctant to invest in EMDE infrastructure. Two recent studies construct new datasets to estimate the social and private returns to infrastructure investment in EMDEs. 

In The Social Rate of Return on Road Infrastructure Investments (NBER Working Paper 34501), Anusha Chari, Peter Blair Henry, and Pablo Picardo estimate country-specific social rates...

Irene Yuan Lo, Michael Ostrovsky, and Parag Pathak, editors.

In the mid-1990s, the first Federal Communications Commission spectrum auction and the redesign of the National Residency Matching Program collectively helped to jump-start the field of market design. Since then, extensive research has improved auction design and broken new conceptual ground in addressing multi-agent matching problems. 

This volume summarizes key discoveries and advances in market design over the past three decades and explores…

The US government has long promoted homeownership through subsidies and tax incentives, viewing it as both socially beneficial and a primary pathway to individual wealth accumulation. For the middle class—those in roughly the middle three-fifths of the wealth distribution—housing wealth remains the most important source of financial security and net worth. Homeownership is also widely believed to provide access to better neighborhoods and higher-quality schools. Yet despite these advantages, homeownership entails significant risks. Homeowners are exposed to housing market downturns that can rapidly erode equity, as well as to income and employment shocks that can compromise their ability to meet mortgage obligations. Such disruptions can lead to delinquency and, in severe cases, the loss of one’s home. Although…

Death rates due to drug poisonings began to surge in the US in the mid-1990s, marking the emergence of an epidemic that has persisted for three decades. The health consequences have been stark, with annual deaths exceeding 100,000 since 2021.

In Prescription for Disaster: The SSDI Rate, Pain, and Prescribing Practices (NBER Working Paper 34265), William N. Evans and Ethan M. J. Lieber examine characteristics of counties in 1990—prior to the surge—that predict the county-level severity of opioid deaths after 2000. After considering a wide range of potential determinants, they focus on one factor: the percentage of the working-age population...

Younger entrepreneurs are disadvantaged in small business loan markets because lenders rely heavily on personal credit scores, which favor long histories of repaying debt. In Modernizing Access to Credit for Younger Entrepreneurs: From FICO to Cash Flow (NBER Working Paper 33367), researchers Christopher M. Hair, Sabrina T. Howell, Mark J. Johnson, and Siena Matsumoto document this fact and show that younger entrepreneurs benefit from underwriting that augments personal credit scores (like FICO) with cash flow data. They analyze comprehensive…