Summer Institute 2025

More than 2,800 researchers, hailing from 31 countries, traveled to Cambridge for the 48th annual NBER Summer Institute, which was held over three weeks in mid-July. The Summer Institute included 50 distinct workshops that were arranged by more than 150 organizers. Most of the meetings were streamed on the NBER’s YouTube channel.

The participants represented 432 universities, central banks, think tanks, businesses, and government agencies. About one third of the participants were NBER affiliates; over 500 were first-time Summer Institute participants.

The 602 research papers presented during the course of the Summer Institute were selected from 3,448 submissions, implying an acceptance rate of 17.4 percent. 

NBER Research Associate and former Council of Economic Advisers chair N. Gregory Mankiw of Harvard University presented the Martin Feldstein Lecture on "The Fiscal Future." He described the prospective growth of US government debt, which some projections suggest will lead to a debt-to-GDP ratio of 1.5 by mid-century. He analyzed five possible strategies for achieving a more sustainable fiscal path—extraordinary economic growth, government default, large-scale money creation, substantial spending cuts, and large tax increases—and concluded that significant tax increases, potentially including a value-added tax, are the likely outcome. 

Kosuke Imai and Research Associate Raj Chetty, both of Harvard University, delivered the Methods Lectures on “Uncovering Causal Mechanisms: Mediation Analysis and Surrogate Indices.” They described both the theory behind and the application of new tools for drawing inferences about the long-term consequences of policy interventions when only short-term outcomes can be measured. They showed how in such settings, well-identified causal effects of short-run consequences could be combined with other data sources to bound potential long-term effects.