Department of Economics

Safe asset shortages can expose an economy to liquidity traps. The nature of these traps is determined by the cyclicality of the bond premium. A counter-cyclical bond premium opens the possibility of expectations-driven liquidity traps in which small issuances of government debt crowd out private debt and reduce output. In contrast, when the bond premium is pro-cyclical and the economy is in a liquidity trap, government debt is expansionary. In the data, we find evidence of a counter-cyclical bond premium. Large interventions can prevent the emergence of self-fulfilling traps, but they require sufficient fiscal capacity. In a quantitative model calibrated to the Great Recession, a promise to increase the government debt-to-GDP ratio by 20 percentage points precludes the possibility of self-fulfilling traps.

Do exchange rate movements matter for how markets price foreign currency denominated sovereign bonds? High-frequency bond price data from 1931 show that depreciation against the dollar/gold was associated with elevated risk premia on US dollar/gold public debt. We use a theoretical model to illustrate how foreign currency debt influences exchange rate policy and foreign currency bond prices. We use these theoretical results, the timing of sterling's devaluation in September 1931, and historically determined fundamentals to identify the impact of exchange rate policy on hard-currency bond yields in the Great Depression.

Using data on the NBER working paper series, we show that the dissemination of economics research suffers from a congestion problem: An increase in the number of weekly released working papers on average reduces downloads, abstract views, and media attention for each paper. Subsequent publishing and citation outcomes are harmed as well. Papers written by prominent authors are not immune to this congestion effect. Finally, suggestive evidence on viewership and downloads implies that working papers substitute for the dissemination function of publication. Our results highlight how readers face time and cognitive constraints, with increased congestion in working papers leading to real impacts on how research is consumed.

Emigration of young, highly educated individuals may deprive origin countries of entrepreneurs. We identify exogenous variation in emigration from Italy by interacting past diaspora networks and current economic pull factors in destination countries. We find that a 1 standard deviation increase in the emigration rate generates a 4.8 percent decline in firms’ creation in the local labor market of origin. An accounting exercise decomposes the estimated effect into four components: subtraction of individuals with average entrepreneurial propensity, selection of young and college-educated among emigrants, negative spillovers on firm creation, and selection on unobservable characteristics positively associated with entrepreneurship.

The COVID-19 pandemic produced a significant decline in international immigration to the USA between 2020 and 2021. This paper documents the timing, characteristics, and heterogeneity of the change in immigration across states and economic sectors. Additionally, we describe the trends in internal native mobility in the USA prior to and after the pandemic, investigating whether natives responded to the decrease in immigration by relocating either geographically or across sectors. Despite the substantial drop in international migration, we do not observe any significant changes in native internal mobility. Employing a panel regression and a shift-share IV, we study the effect of foreign immigration, the emergence of remote-work, and changes in labor demand on cross-state native mobility. Our results indicate that the decline in immigration following COVID-19 and the differential availability of remote-work opportunities across sectors and states did not drive changes in natives’ cross- state or cross-sector mobility.

We examine multi-generational impacts of positive in utero health interventions using a new research design that exploits sharp increases in prenatal Medicaid eligibility that occurred in some states. Our analyses are based on U.S. Vital Statistics Natality files, which enables linkages between individuals' early life Medicaid exposure and the next generation's health at birth. We find evidence that the health benefits associated with treated generations' early life program exposure extend to later offspring. Our results suggest that the returns on early life health investments may be substantively underestimated.

The ‘China shock’ operated in part through the housing market, which is one reason why its impact was so large on the U.S. labor market. We add housing to a multi-region multi-sector model, with individuals choosing whether and where to work. Controlling for housing reduces the negative direct impact of import exposure on manufacturing employment by 26%–31%, with a significant magnification through the housing market. A variance decomposition analysis shows that the indirect effect of the China shock through the housing market contributes an added 11% to the variance in manufacturing employment as compared to the direct effect of import exposure. For manufacturing and construction employment combined, the indirect effect even outweighs the direct effect.

National and international flows of knowledge are fundamental determinants of technological progress. In this article we review the existing literature on knowledge flows and we propose a method for estimating them, based on patent citations. Citations are links between inventions that reveal a learning process at the technological frontier. We use data for the period 1975-1996 for 147 subnational regions in Europe and North America. We find that geographical distance and technological differences constitute major barriers to knowledge flows. We also show that these flows may have positive, but small, effect on total factor productivity.