The 10 most-cited articles in American Economic Review, 2017

Governments regularly subsidize new ventures to spur innovation. This paper conducts the first large-sample, quasi-experimental evaluation of R&D subsidies. I use data on ranked applicants to the U.S. Department of Energy’s SBIR grant program. An award approximately doubles the probability that a firm receives subsequent venture capital and has large, positive impacts on patenting and commercialization. These effects are stronger for more financially constrained firms. Certification, where the award contains information about firm quality, likely does not explain the grant effect on funding. Instead, the grants seem to reduce investor uncertainty by funding technology prototyping.

This address considers the epidemiology of narratives relevant to economic fluctuations. The human brain has always been highly tuned toward narratives, whether factual or not, to justify ongoing actions, even such basic actions as spending and investing. Stories motivate and connect activities to deeply felt values and needs. Narratives “go viral” and spread far, even worldwide, with economic impact. The 1920–1921 Depression, the Great Depression of the 1930s, the so-called Great Recession of 2007–2009, and the contentious political-economic situation of today are considered as the results of the popular narratives of their respective times. Though these narratives are deeply human phenomena that are difficult to study in a scientific manner, quantitative analysis may help us gain a better understanding of these epidemics in the future. (JEL D72, E32, G01, N10)

We examine the impact of policy uncertainty on trade, prices, and real income through firm entry investments in general equilibrium. We estimate and quantify the impact of trade policy on China's export boom to the United States following its 2001 WTO accession. We find the accession reduced the US threat of a trade war, which can account for over one-third of that export growth in the period 2000– 2005. Reduced policy uncertainty lowered US prices and increased its consumers' income by the equivalent of a 13-percentage-point permanent tariff decrease. These findings provide evidence of large effects of policy uncertainty on economic activity and the importance of agreements for reducing it. (JEL D72, F13, F14, O19, P33)

We employ a discrete choice experiment in the employment process for a national call center to estimate the willingness to pay distribution for alternative work arrangements relative to traditional office positions. Most workers are not willing to pay for scheduling flexibility, though a tail of workers with high valuations allows for sizable compensating differentials. The average worker is willing to give up 20 percent of wages to avoid a schedule set by an employer on short notice, and 8 percent for the option to work from home. We also document that many job-seekers are inattentive, and we account for this in estimation. (JEL J22, J31, J80, L84)

We examine the effects of trade liberalization in China on the evolution of markups and productivity of manufacturing firms. Although these dimensions of performance cannot be separately identified when firm output is measured by revenue, detailed price deflators make it possible to estimate the average effect of tariff reductions on both. Several novel findings emerge. First, cuts in output tariffs reduce markups, but raise productivity. Second, pro-competitive effects are most important among incumbents, while efficiency gains dominate for new entrants. Third, cuts in input tariffs raise both markups and productivity. We highlight mechanisms that explain these findings in the Chinese context. (JEL D24, F13, L25, L60, O14, P31, P33)

We combine original geo-referenced data on mining extraction of 15 minerals with information on conflict events at spatial resolution of 0.5o x 0.5o for all Africa over 1997-2010. Exploiting exogenous variations in world prices, we find a positive impact of mining on conflict at the local level. Quantitatively, the historical rise in prices (commodity super-cycle) explains 15-25 percent of average country-level violence in Africa. We then document how the appropriation of a mining area by a fighting group contributes to the escalation from local to global violence. Finally, we analyze the impact of corporate practices and transparency initiatives in the mining industry.

We measure the persuasive effects of slanted news and tastes for like-minded news, exploiting cable channel positions as exogenous shifters of cable news viewership. Channel positions do not correlate with demographics that predict viewership and voting, nor with local satellite viewership. We estimate that Fox News increases Republican vote shares by 0.3 points among viewers induced into watching 2.5 additional minutes per week by variation in position. We then estimate a model of voters who select into watching slanted news, and whose ideologies evolve as a result. We use the model to assess the growth over time of Fox News influence, to quantitatively assess media-driven polarization, and to simulate alternative ideological slanting of news channels. (JEL D72, L82)

We study the evolution of trade liberalization's effects on Brazilian local labor markets. Regions facing larger tariff cuts experienced prolonged declines in formal sector employment and earnings relative to other regions. The impact of tariff changes on regional earnings 20 years after liberalization was three times the effect after 10 years. These increasing effects on regional earnings are inconsistent with conventional spatial equilibrium models, which predict declining effects due to spatial arbitrage. We investigate potential mechanisms, finding empirical support for a mechanism involving imperfect interregional labor mobility and dynamics in labor demand, driven by slow capital adjustment and agglomeration economies. This mechanism gradually amplifies the effects of liberalization, explaining the slow adjustment path of regional earnings and quantitatively accounting for the magnitude of the long-run effects. (JEL F16, J23, J31, J61, O15, O19, R23)

Gender differences in task allocations may sustain vertical gender segregation in labor markets. We examine the allocation of a task that everyone prefers be completed by someone else (writing a report, serving on a committee, etc.) and find evidence that women, more than men, volunteer, are asked to volunteer, and accept requests to volunteer for such tasks. Beliefs that women, more than men, say yes to tasks with low promotability appear as an important driver of these differences. If women hold tasks that are less promotable than those held by men, then women will progress more slowly in organizations. (JEL I23, J16, J44, J71, M12, M51)

The recent fall of labor's share of GDP in numerous countries is well-documented, but its causes are poorly understood. We sketch a “superstar firm” model where industries are increasingly characterized by “winner take most” competition, leading a small number of highly profitable (and low labor share) firms to command growing market share. Building on Autor et al. (2017), we evaluate and confirm two core claims of the superstar firm hypothesis: the concentration of sales among firms within industries has risen across much of the private sector; and industries with larger increases in concentration exhibit a larger decline in labor's share.