Economics

In instrumental-variable (IV) studies, researchers often evaluate multiple candidate instruments and selectively report the specification with the most favorable first- or second-stage statistics. We show that this form of instrument selection (“instrument-hacking”) induces median bias in IV estimators toward the OLS estimand, undermining the rationale for using IV. When all candidate instruments have the same true strength, median bias increases monotonically with the number of available instruments. More generally, when candidate instruments differ in true strength, monotonicity need not hold because increasing the number of instruments can lead researchers to select genuinely stronger..

We design a method for measuring the risk preferences of agents in the deep past. The method combines a structural model of crop choice as a portfolio allocation with machine-learning prediction of expected crop returns, using historic agronomic and climate data. We estimate county-level risk preferences for the United States and farmer-level preferences in Kansas from 1889 to 1929. More risk averse farmers leveraged less, were less likely to purchase novel WWI Liberty Bonds, and were more likely to participate in local risk-sharing institutions. We show that higher risk aversion predicts slower tractor adoption and farm mechanization during the 1920s.

We examine whether occupational licensing improves service quality and safety using trip-level Uber data that include driver ratings and telematics-based measures of driving behavior. Exploiting quasi-random assignment from proximity-based dispatch, we compare trips served by licensed and unlicensed drivers in two settings: a cross-border comparison between New York City and New Jersey, and a deregulation event in Houston. Across settings and specifications, including instrumental variable estimates, we find no consistent evidence that licensing improves consumer outcomes. In Houston, post-deregulation entrants are indistinguishable from previously licensed drivers on ratings and driving beh..

I decompose stock returns into a duration-matched Treasury component, identified from monetary policy surprises, and a payoff component. Risk and returns rise much less with duration for stocks than for their matched Treasuries. Stock volatility is dampened by rate insurance: rates fall in bad times, so the bond inside a stock provides insurance against the stock’s payoff risk. Expected stock returns are dampened because the insurance works in reverse: rates rise in good times, so stocks’ payoff gains hedge the losses borne by investors holding net duration, notably government bonds when Ricardian equivalence fails. This framework helps reconcile positive bond premia with negative stock-..

Firms shape public policy not only from the outside through lobbying and campaign contributions, but also from the inside when business owners hold public office. We study this channel using a novel dataset that links state legislators’ personal financial disclosures to bill sponsorship records across 26 U.S. states from 2009 to 2023. The disclosures allow us to observe business ownership during legislative service and to distinguish entrepreneurs, defined as legislators who both own and actively manage a firm, from passive shareholders and employees. Applying a large language model to bill text, we classify legislation as pro-business and identify a subset of pro-entry bills that reduce b..

How slow are bank transfers, and how do transfer delays affect deposit demand? Using transaction-level data from millions of depositors, we measure transfer delays by matching debits and credits across accounts held by the same depositor. Shorter delays correlate with more transfers and lower balances. Exploiting county-level exposure to Zelle’s staggered rollout, we find that faster payments reduce delays and deposit growth. Calibrating a deposit-management model, we find that transfer delays raise deposit demand, and the magnitude of this effect varies with interest rates and consumption volatility. Payment frictions therefore shape transactional deposit demand and monetary transmission.

We examine how contractions in local labor demand during the Great Recession affected children's academic achievement. We combine county-level test scores for grades 3–8 from the Stanford Education Data Archive with a shift-share design that interacts counties' 2005 industry composition with national industry employment growth, isolating demand-driven changes in local employment. Following recent advances in the shift-share literature, we validate the design with balance, pre-trend, and Rotemberg-weight diagnostics and report exposure-robust standard errors throughout. A one-standard-deviation adverse shock lowers mathematics achievement by about 0.03 student-level standard deviations and ..

How do firms set wages? How should governments set income taxes? If labor supply is inelastic to wages, firms can pay workers less than their marginal products, and governments can increase taxes without eroding the base. However, the structure of labor supply elasticities in the economy is complex. Recent empirics document variation across workers, firms, and margins (which firm to work at versus how many hours to work). To account for this rich structure of labor supply elasticities we extend the neoclassical model to include a discrete choice over which firm to work at, production complementarities and strategic interaction between heterogeneous, granular firms. In terms of wage setting, ..

Public AI benchmarks steer research and allocate investments. They are therefore market designs. Public examples can reveal the process behind a private final test, while a finite public score cannot cover a broad task space inherent to general intelligence. I show how both gaps become profitable when scores move capital and how targeted effort erodes the signal used by later investors. The market design lesson is to separate development from certification: publish practice tasks, but choose the investment-consequential generator after the submitted system's evaluation policy is fixed.

The possibility of fiscal dominance in the representative-agent New Keynesian model (RANK) hinges on the assumption that income is perpetually demand-determined: fiscal deficits can drive output and inflation within that model only insofar as they trigger infinitely lasting, self-sustained shifts in aggregate spending and income. Moving to heterogeneous-agent New Keynesian models (HANK) opens the door to a different pathway: classical non-Ricardian effects, due to finite horizons or liquidity constraints. A refinement motivated by the model's intended focus on short-run phenomena—requiring a return to flexible-price outcomes in finite time—arrests the infinite feedback loop between spend..

Survival analysis methods are often used to predict the time until the onset of an event in settings when the true time-to-event (TTE) may be censored during training. Such approaches typically assume uncensored data are representative of censored data and that the probability of censoring conditioned on the covariates remains constant over time, i.e., there is no censoring distribution shift. However, both assumptions can fail in practice when censoring results from interventions targeted to individuals with particular comorbidities or genetic markers (such as prophylactic surgery when predicting time to cancer onset, or scheduled cesarean delivery and induction when predicting time to spon..

Support for populist and authoritarian regimes is rising worldwide, despite evidence that they tend to underperform economically. We examine the role of (mis)perceptions of regime performance as drivers of political attitudes, leveraging two survey experiments with 11,377 respondents during Argentina’s 2023 presidential elections. Optimistic beliefs about the performance of populist and non-democratic regimes were widespread, and displayed a strong correlation with support for these regimes. When exposed to randomly assigned informational treatments challenging optimistic views about these political regimes, individuals significantly adjusted their beliefs, and reduced their support for ca..

The diffusion of technological innovation depends on incentives, regulations, and firms’ strategic behaviors. We study these intersections within cardiac procedure markets following Medicare’s expansion of non-hospital facility options for treatment, enabled by clinical advancements. State-level regulations restrain federal pro-competition policy. Where market entry occurs, business stealing is concentrated among the lowest cost treatment settings, rather than high-cost hospitals––increasing Medicare spending by approximately $2.5 million. Medicare policy also generates externalities for untargeted procedures and other payers, except when hospitals and physicians are vertically integ..