NBER工作论文2021年5月10日

The effects of large banks on the real economy are theoretically ambiguous and politically controversial. I identify quasi-exogenous increases in bank size in postwar Germany. I show that firms did not grow faster after their relationship banks became bigger. In fact, opaque borrowers grew more slowly. The enlarged banks did not increase profits or efficiency, but worked with riskier borrowers. Bank managers benefited through higher salaries and media attention. The paper presents newly digitized microdata on German firms and their banks. Overall, the findings reveal that bigger banks do not always raise real growth and can actually harm some borrowers.

We use admissions lotteries to estimate the effects of large-scale public preschool in Boston on college-going, college preparation, standardized test scores, and behavioral outcomes. Preschool enrollment boosts college attendance, as well as SAT test-taking and high school graduation. Preschool also decreases several disciplinary measures including juvenile incarceration, but has no detectable impact on state achievement test scores. An analysis of subgroups shows that effects on college enrollment, SAT-taking, and disciplinary outcomes are larger for boys than for girls. Our findings illustrate possibilities for large-scale modern, public preschool and highlight the importance of measuring long-term and non-test score outcomes in evaluating the effectiveness of education programs.

Despite growing interest in improving early-childhood education in developing countries, there is little evidence on cost-effective ways of doing so at scale. We use a large-scale randomized experiment to study the impact of adding an extra worker focused on pre-school education (for children aged 3-5) in the world’s largest public early-childhood program: India’s Integrated Child Development Services (ICDS). Adding a worker doubled net instructional time and led to 0.29 and 0.46 standard deviation increases in math and language test scores after 18 months for children who remained enrolled in the program. Rates of stunting and severe malnutrition were also lower in the treatment group, likely reflecting the effect of freeing up time of the incumbent worker to focus more on nutrition-related tasks. A cost-benefit analysis suggests that the benefits of the program are likely to significantly exceed its costs even under conservative assumptions.

We measure extensive-margin labor supply (employment) preferences in two representative surveys of the U.S. and German populations. We elicit reservation raises: the percent wage change that renders a given individual indifferent between employment and nonemployment. It is equal to her reservation wage divided by her actual, or potential, wage. The reservation raise distribution is the nonparametric aggregate labor supply curve. Locally, the curve exhibits large short-run elasticities above 3, consistent with business cycle evidence. For larger upward shifts, arc elasticities shrink towards 0.5, consistent with quasi-experimental evidence from tax holidays. Existing models fail to match this nonconstant, asymmetric curve.

The covered interest rate parity (CIP) condition is a fundamental arbitrage relationship in international finance. In this chapter, we review its breakdown during the Global Financial Crisis and its continued failure in the subsequent decade. We review how to measure CIP deviations, discuss the drivers of CIP deviations, and the implications of CIP deviations for global financial markets.

By age 77 a plurality of women in wealthy Western societies are widows. Comparing older (aged 70+) married women to widows in the American Time Use Survey 2003-18 and linking the data to the Current Population Survey allow inferring the short- and longer-term effects of an arguably exogenous shock—husband’s death—and measuring the paths of adjustment of time use to it. Widows differ from otherwise similar married women, especially from married women with working husbands, by cutting back on home production, mainly food preparation and housework, mostly by engaging in less of it each day, not doing it less frequently. French, Italian, German, and Dutch widows behave similarly. Widows are alone for 2/3 of the time they had spent with their spouses, with a small increase in time with friends and relatives shortly after becoming widowed. Evidence from the European countries shows that widows feel less time stress than married women but are also less satisfied with their li! ves. Following older women in 18 European countries before and after a partner’s death shows that widowhood reduces their feelings of time pressure. U.S. longitudinal data demonstrate that it increases feelings of depression. Most of the adjustment of time use in response to widowhood occurs within one year of the husband’s death; but feelings of reduced time pressure and of depression persist much longer.

We exploit novel data from brain-training games to examine the impacts of air pollution on a comprehensive set of cognitive skills of adults. We find that exposure to particulate matter (PM2.5) impairs adult cognitive function, and that these effects are largest for those in prime working age. These results confirm a hypothesized mechanism for the impacts of air pollution on productivity. We also find that the cognitive effects are largest for new tasks and for those with low ability, suggesting that air pollution increases inequality in workforce productivity.

We define high cost lenders as lenders that issue a disproportionate number of high cost loans. We develop a shift-share measure to capture the market representation of these high cost lenders in housing submarkets. After conditioning on housing submarket fixed effects, origination year fixed effects and trends over origination years based on housing submarket attributes, the magnitude of the estimated relationship is very stable as detailed controls for borrower attributes, credit score and loan terms are added. The relationship between the representation of high cost lenders and foreclosure is broad based across borrowers and types of loans, but is strongest for loans originated by high cost lenders whether or not the loans themselves are high cost. We investigate three potential mechanisms: reverse causality where high cost lenders respond to an increase in demand from higher risk borrowers, the types of mortgages issued when high cost lenders increase their market presen! ce, and the behavior of loan servicers when a cohort of loans contains a large number of loans issued by high cost lenders. While we do not have direct information on loan servicers, our evidence points towards foreclosure decisions during the crisis as the primary mechanism behind our findings.

The “debt-overhang hypothesis” – that households cut back more on their spending in a crisis when they have higher levels of outstanding mortgage debt (Dynan, 2012) – seems to be taken for granted by macroprudential authorities in several countries in their policy decisions, as well as by the international organizations that evaluate and comment on countries’ macroprudential policy. New results for Australian microdata are presented that reject the debt-overhang hypothesis. The results instead support the “spending-normalization hypothesis” of Andersen, Duus, and Jensen (2016), what can also be called the “debt-financed overspending” hypothesis – that the correlation between high pre-crisis household indebtedness and subsequent spending falls during the crisis reflects high debt-financed spending pre-crisis and a return to normal spending during the crisis. As discussed in Svensson (2019, 2020), this is consistent with the above correlation reflecting deb! t-financed overspending through what Muellbauer (2012) calls the “housing-collateral household demand” channel and Mian and Sufi (2018) the “debt-driven household demand” channel.

We propose a general equilibrium economy with oligopolistic output markets in which two channels can cause a change in market power: (i) technology, via changes to productivity shocks and the cost of entry, (ii) market structure, via changes to the number of potential competitors. First, we disentangle these narratives by matching time-series on markups, labor reallocation and costs between 1980 and 2016, finding that both channels are necessary to account for the data. Second, we show that changes in technology and market structure over this period yielded positive welfare effects from reallocation and selection, but off-setting negative effects from deadweight loss and overhead. Overall, welfare is 9 percent lower in 2016 than in 1980. Third, the changes we identify replicate cross-sectional patterns in declining business dynamism, declining equilibrium wages and labor force participation, and sales reallocation toward larger, more productive firms.

The poor live paycheck to paycheck and are repeatedly exposed to strong cyclical income fluctuations. We investigate whether such income fluctuations affect risk preference among the poor. If risk preference temporarily changes around payday, optimal decisions made before payday may no longer be optimal afterward, which could reinforce poverty. By exploiting Social Security payday cycles in the US, we find that risk preference among the poor relying heavily on Social Security changes around payday. Rather than cognitive decline before payday, the deterioration of mental health and relative deprivation may play a role. We find similar evidence among the Japanese elderly.

This paper overviews the data collection procedures and resulting data for inventor ages and associated death dates. We use information about inventors from patents (name and location) and search for age and date of death information from publicly available online web directories and build a scoring system to indicate the quality of information that we collect. After applying a variety of heuristics and robustness checks, we are confident of 1,508,676 inventor ages associated with patents granted between 1976 and 2018. We also find the death dates of 206,589 inventors, though we are not as confident of the accuracy of the death information. The datasets and associated replication files are freely available at: https://doi.org/10.7910/DVN/YRLSKU

This paper investigates the role of private equity (PE) in failed bank resolutions after the 2008 financial crisis, using proprietary FDIC failed bank acquisition data. PE investors made substantial investments in underperforming and riskier failed banks, particularly in geographies where local banks were also distressed, filling the gap created by a weak, undercapitalized banking sector. Using a quasi-random empirical design based on detailed bidding information, we show PE-acquired banks performed better ex post, with positive real effects for the local economy. Overall, PE investors had a positive role in stabilizing the financial system through their involvement in failed bank resolution.

Gun buyback programs (GBPs), which use public funds to purchase civilians' privately-owned firearms, aim to reduce gun violence. However, little is known about their effects on firearm-related crime or deaths. Using data from the National Incident Based Reporting System, we find no evidence that GBPs reduce gun crime. Given our estimated null findings, with 95 percent confidence, we can rule out decreases in firearm-related crime of greater than 1.3 percent during the year following a buyback. Using data from the National Vital Statistics System, we also find no evidence that GBPs reduce suicides or homicides where a firearm was involved.

Large-scale increases in discrimination can lead to dismissals of highly qualified managers. We investigate how expulsions of senior Jewish managers, due to rising discrimination in Nazi Germany, affected large corporations. Firms that lost Jewish managers experienced persistent reductions in stock prices, dividends, and returns on assets. Aggregate market value fell by roughly 1.8 percent of German GNP because of the expulsions. Managers who served as key connectors to other firms and managers who were highly educated were particularly important for firm performance. The findings imply that individual managers drive firm performance. Discrimination against qualified business leaders causes first-order economic losses.

Regulatory debates about centralized trading assume security design is immune to market structure. We consider a regulator who introduces an exchange to increase liquidity, understanding that security design is endogenous. For a given security, investors would like to trade in a larger market and, for a given market structure, they would like to trade a safer security. We show that financial intermediaries design riskier securities after the exchange is introduced, even when the exchange leads to the origination of safer underlying assets. The results reflect a relative dilution of investor market power and motivate coordinated policies to improve investor welfare.

In the absence of first-best climate policy, we demonstrate that existing government institutions and policy established for reasons unrelated to climate change may induce climate adaptation. We examine the impact of temperature on ambient ozone concentration in the United States from 1980-2013, and the role of institution-induced adaptation. Ozone is formed under warm temperatures, and regulated by the Clean Air Act institution. Adaptation in counties out of attainment with air quality standards is 107 percent larger than under attainment, implying substantial institution-induced adaptation. Furthermore, local beliefs about climate change appear to reinforce adap- tive behavior, suggesting a nontrivial role in second-best climate policy.

Inspired by the field experiment in Bertrand and Morse (2011), the state of Texas adopted an information disclosure for consumers taking out payday loans starting in January, 2012. The disclosure compares the cost of payday loans with other credit products, and presents their likelihood of renewal in easy-to-understand terms. Simultaneously, Austin and Dallas implemented stricter supply restrictions through city ordinances. We analyze both types of regulations, and find that the statewide disclosures led to a significant and persistent 13% decline in loan volume in the first six months after implementation. The city ordinances led to a 62% decline in loan volume in Austin and a 20% decline in Dallas, with the timing of the effect driven by the start of enforcement rather than the effective date of regulation. The results show that both behaviorally-motivated disclosures and city-level supply restrictions can have a significant impact on equilibrium loan quantities, with no e! ffect on prices or evidence of evasive income falsification.

Why do cities differ so much in productivity? Using a split-sample IV strategy, we document that up to three quarters of the large measured dispersion in productivity across US cities is spurious and reflects the "luck of the draw" of idiosyncratically heterogeneous plants. Due to this granularity bias, economies with randomly reallocated plants exhibit nearly as high a variance as the empirical economy. For new plants, four fifths of the raw dispersion reflects granularity bias, and their productivity is only imperfectly correlated with that of older plants, which dominate measured productivity levels. These US-based patterns broadly extend to European countries.

Children exposed to pollutants like lead are more disruptive and have lower achievement. However, little is known about whether lead-exposed children affect the long-run outcomes of their peers. We estimate these spillover effects using new data on preschool blood lead levels (BLLs) matched to education data for all students in North Carolina public schools. We compare siblings whose school-grade cohorts differ in the proportion of children with elevated BLLs, holding constant school and peers’ demographics. Having more lead-exposed peers is associated with lower high-school graduation and SAT-taking rates and increased suspensions and absences. Peer effects are larger for same-gendered students.

Immigrant founders of venture capital-backed companies have been critical to the entrepreneurial ecosystem. We document the channels through which immigrant founders find their way to the United States and how those channels have changed over time. Immigrants have been an important source of founders for venture capital-backed startups accounting for roughly 20% of all founders over the past 30 years. Immigrants coming to the United States for their education have been the primary source of founders with those coming after being educated abroad and then arriving for work decreasing in importance over time. The importance of undergraduate education as a channel for immigrant founders has increased over time. Immigrant founders coming for education are likely to start their companies in the state in which they were educated, especially states where they received their graduate education, leading to potentially large local economic benefits. The results of this paper have impor! tant policy implications for the supply of entrepreneurial talent and efforts to promote entrepreneurial ecosystems.

This paper studies the evolution of individual earnings inequality and dynamics in Canada from 1983 to 2016 using tax files and administrative records. Linking these individuals to their employers (and rich administrative records on firms) beginning in 2001, it also documents the relationship between the earnings dynamics of workers and the size and growth of their employers. It highlights three main patterns over this period: First, with a few exceptions (sharp increase in top 1% and declining gender gap), Canada has experienced relatively modest changes in overall earnings inequality, volatility, and mobility between 1983 and 2016. Second, there is considerable variability in earnings inequality and volatility over the business cycle. Third, the earnings dynamics of individuals are strongly related to the size and employment growth of their employers.

I use a model of private and public behavior to mitigate disease transmission during the COVID pandemic over the past year in the United States to address two questions: What dynamics of infections and deaths should we expect to see from a pandemic? What are our options for mitigating the impact of a pandemic on public health? I find that behavior turns what would be a short and extremely sharp epidemic into a long, drawn out one. Absent the development of a technological solution such as vaccines or life-saving therapeutics, additional public health interventions suffer from rapidly diminishing returns in improving long-run outcomes. In contrast, rapidly implemented non-pharmaceutical interventions, in combination with the rapid development of technological solutions, could have saved nearly 300,000 lives relative to what is now projected to occur.

This essay is the introduction to a book of the same title, forthcoming in summer of 2021 from Oxford University Press. The purpose is to document the ways in which patent systems are products of battles over the economic surplus from innovation. The features of these systems take shape as interests at different points in the production chain seek advantage in any way they can, and consequently, they are riven with imperfections. The interesting historical question is why US-style patent systems with all their imperfections have come to dominate other methods of encouraging inventive activity. The essays in the book suggest that the creation of a tradable but temporary property right facilitates the transfer of technological knowledge and thus fosters a highly productive decentralized ecology of inventors and firms.

Recent expansions of Medicaid eligibility have come with increased experimentation with enrollee cost-sharing. In this paper, we exploit a discontinuous premium increase at the federal poverty level in Michigan’s Medicaid expansion program to test low-income individuals’ sensitivity to premiums using linked enrollment and claims data. At the cutoff, average premiums increase by $3.15 and the probability of disenrollment increases by 2.3 percentage points. Increased disenrollment occurs among those with fewer documented medical needs at baseline, but not among those with greater medical needs. These results suggest healthier low-income individuals may be sensitive to even modest health insurance premiums, and that premiums may induce adverse selection in Medicaid plans.

We provide a general non-parametric characterization of how welfare responds to changes in budget and production possibility sets when preferences are non-homothetic or subject to shocks, in both partial and general equilibrium. We generalize Hulten’s theorem, which is the basis for constructing aggregate quantities, to this context. We identify a new bias in measures of real consumption that depends on the covariance of price changes and expenditure changes due to income effects or preference shocks. We apply our results to long-run and short-run phenomena. In the long-run, we show that structural transformation, if caused by income effects, is roughly twice as important for welfare than what is implied by standard measures of Baumol’s cost disease. In the short-run, we show that when firms’ demand shocks are correlated with their supply shocks, industry-level price and output indices are biased, and this bias does not disappear in the aggregate. Finally, we show that! correlated supply and demand shifters make real GDP and aggregate TFP unreliable metrics for measuring production and productivity, and we illustrate this using the Covid-19 crisis.

We study the welfare effects of offering choice over financial coverage levels––"vertical choice''––in regulated health insurance markets. Though the efficient level of coverage, which trades off the value of risk protection and the social cost from moral hazard, likely varies across consumers, we emphasize that this variation alone is not sufficient to motivate choice. When premiums cannot reflect individual costs, consumers may not select their efficient coverage level. We show that vertical choice is efficient only if consumers with higher willingness to pay for insurance have a higher efficient level of coverage. Using administrative data from a large public employer, we investigate this condition empirically and find that the welfare gains from vertical choice are either zero or economically small.

This paper examines the effect of fall 2020 school reopenings in Texas on county-level COVID-19 cases and fatalities. Previous evidence suggests that schools can be reopened safely if community spread is low and public health guidelines are followed. However, in Texas, reopenings often occurred alongside high community spread and at near capacity, making it difficult to meet social distancing recommendations. Using event-study models and hand-collected instruction modality and start dates for all school districts, we find robust evidence that reopening Texas schools gradually but substantially accelerated the community spread of COVID-19. Results from our preferred specification imply that school reopenings led to at least 43,000 additional COVID-19 cases and 800 additional fatalities within the first two months. We then use SafeGraph mobility data to provide evidence that spillovers to adults’ behaviors contributed to these large effects. Median time spent outside the hom! e on a typical weekday increased substantially in neighborhoods with large numbers of school-age children, suggesting a return to in-person work or increased outside-of-home leisure activities among parents.

This paper investigates whether education weakens the relationship between early-life disadvantages and later-life SES. We use three proxies for advantage that we show are independently associated with SES in middle-age. Besides early, favorable family and neighborhood conditions, we argue that the genes a child inherits also represent a source of advantages. Using a regression discontinuity design and data for over 110,000 individuals, we study a compulsory schooling reform in the UK that generated exogenous variation in schooling. While the reform succeeded in reducing educational disparities, it did not weaken the relationship between early-life disadvantages and wages. This implies that advantaged children had higher returns to schooling. We exploit family-based random genetic variation and find no evidence that these higher returns were driven by genetically-influenced individual characteristics such as innate ability or skills.

Pharmaceutical innovation policy involves managing a tradeoff between high prices for new products in the short-term and stronger incentives to develop products for the future. Prior research has documented a causal relationship between market size and pharmaceutical research and development (R&D) activities. The existing literature, however, provides no evidence of how this relationship varies across markets. We investigate whether recent expansions in state Medicaid programs caused an increase in R&D. We find no evidence of a response, potentially a result of Medicaid’s low reimbursement for pharmaceuticals, suggesting low(er) price markets may have different dynamics with respect to innovation policy.

We open the black box of the M&A decision process by constructing a comprehensive sample of US firms with specialized M&A staff. We investigate whether specialized M&A staff improves acquisition performance or facilitates managerial empire building instead. We find that firms with specialized M&A staff make better acquisitions when acquisition performance is measured by stock price reactions to announcements, long-run stock returns, operating performance, divestitures, and analyst earnings forecasts. This effect does not hold when the CEO is powerful, overconfident, or entrenched. Acquisitions by firms without specialized staff do not create value, on average. We provide evidence on mechanisms through which specialized M&A staff improves acquisition performance. For identification, we use the staggered recognition of inevitable disclosure doctrine as a source of exogenous variation in the employment of specialized M&A staff.

We show that the specific factors model can be used to derive a rigorous link between movements in stock prices and productivity, wages, employment, output, and welfare. We also prove that the commonly used measure of the effective rate of protection equals the dual measure of revenue TFP, providing a theoretical foundation for why many studies have found that trade liberalization significantly increases firm-level productivity. Our method enables us to trace a tariff announcement's effect on TFP through its impact on macro variables (e.g., exchange rates) and through its effect on the relative prices of imports. We apply this framework to understanding the implications of the U.S.-China trade war. Our results show that the trade-war announcements caused large declines in U.S. stock prices, expected TFP, and expected inflation largely by moving macro variables, but also by causing declines in the returns of firms trading with China. We find that markets expect the trade war ! to lower U.S. welfare by 7.8 percentage points, which is much larger than the predictions of static models but in line with those of dynamic models.

In recessions, unemployment increases despite the—perhaps counterintuitive—fact that the number of unemployed workers finding jobs expands. We propose a theory of unemployment fluctuations resting on this countercyclicality of gross flows from unemployment into employment. In recessions, the abundance of new hires “congests” the jobs the unemployed fill—diminishing their marginal product and discouraging further job creation. Countercyclical congestion explains 30-40% of US unemployment fluctuations. Additionally, it explains the excess procyclicality of new hires' wages, the cyclical labor wedge, the large earnings losses from job displacement and from graduating during recessions, and the insensitivity of unemployment to policies such as unemployment insurance.

We examine the extent to which the labor market facilitates the diffusion of tax planning knowledge across firms. Using a novel dataset of tax department employee movements between S&P 1500 firms, we find that firms experience an increase in their tax planning after hiring a tax employee from a tax aggressive firm. This finding is robust to various research designs and specifications. Consistent with tax planning knowledge driving this result, we find that the tax planning benefit of hiring an employee from a tax aggressive firm is stronger when the employee has more tax experience and is hired into a senior tax department role, and when the hiring firm likely had less tax planning knowledge prior to the hire. Further tests suggest that tax planning knowledge is highly specific in nature: the increase in tax avoidance is larger when the hiring and former firms are similar (i.e., operating in the same sector or having similar foreign operations), and firms are more likely to ! hire tax department employees from firms with similar characteristics. Our study documents the first-order role of the labor market in the diffusion of tax planning knowledge across firms, and suggests that tax department human capital is a central determinant of tax planning outcomes.

Previous research suggests creative ability peaks in the age decades of the 30s and early 40s, and declines thereafter, with some variation across fields. Building from the cognitive aging literature, we expect differences in the rate of creation and qualitative nature of creative works by age. Cognitive processes show aging-related changes with increases in experience-based knowledge (pragmatics or crystallized abilities) and decreases in the ability to process novel information quickly and efficiently (mechanics or fluid abilities). We describe a new database created by combining the publicly available patent data with information on inventor ages scraped from directory websites on the web for approximately 1.2 million U.S.-resident inventors patenting between 1976 and 2017. Our results suggest that cross-sectional and within-inventor patenting rates are similar, peaking at around the early 40s for both women and men. We find varying results for attributes of patents in re! lation to age, some of which are consistent with cognitive aging theory. For solo inventors, backward citations and originality, which are connected to experience, were found to increase with age. Forward citations, number of claims, and generality measures, as well as a citation-based measure of disruptiveness decline on average with inventor age. A similar pattern was found for performance in teams based on the average age of inventors in the team. Exploration of age diversity showed that teams with a wider age range had patents that are slightly more important (i.e., with more forward citations). The findings have the potential to advance scholarship on the life course of innovation with implications for workplace policies.

The racial and ethnic composition of home buyers varies across geographic locations. For example, Asians and Hispanics are much more likely to buy homes in California than Blacks and Blacks are more likely to buy homes in Georgia than other demographic groups. Home prices grow at different rates across geographic units such as counties or zip codes. Hedonic bundling inhibits buyers from purchasing shares of different homes and forming a spatially diversified housing portfolio. Spatial variation in purchases suggests that the average rate of return to housing varies across racial and ethnic groups. To test this claim, I construct a geographic shift-share index by combining Zillow geographic specific home price index data with HMDA micro data. The shift share calculations yield the average rate of return to home ownership by purchase year, and sale year for different demographic groups. Over the years 2007 to 2020, Blacks earned a lower rate of return on home purchases than A! sians and Hispanics and the sample average. Within geographic areas, average loan differences across racial and ethnic groups are very small.