Henrik Sigstad

The American Economic Review 116(1) s. 189-208 Doi: https://doi.org/10.1257/aer.20231104

Judge IV designs rely on monotonicity—each judge being weakly stricter than more lenient judges in all cases. I measure monotonicity in judicial panels in five different settings and find that it is violated in up to 50 percent of nonunanimous cases. The monotonicity violations are not detected by conventional tests, but they would typically induce little bias in judge IV estimates. (JEL C26, K41, K42, O17)

Review of Economic Studies s. 1-39 Doi: https://doi.org/10.1093/restud/rdae073

Do judges respond to reversals of their decisions? Using random assignment of cases across two stages of the criminal justice system in Norway and a novel dataset linking trial court decisions to reversals in appeals courts, we provide causal evidence on feedback effects in judicial decision-making. By exploiting differences in the tendencies of randomly assigned appeal panels to reverse trial court decisions, we show that trial court judges who receive a reversal of a sentence respond by updating the likelihood of imposing a prison sentence in the direction of the reversal in future cases. Consistent with a Bayesian learning model, we find that the responses are stronger for judges with weaker priors and for reversals corresponding to stronger signals. Our estimates, however, also indicate that judges overreact to reversals compared to Bayes’ rule.

Journal of Econometrics 242(1) s. 1-18 Doi: https://doi.org/10.1016/j.jeconom.2024.105785

We study what two-stage least squares (2SLS) identifies in models with multiple treatments under treatment effect heterogeneity. Two conditions are shown to be necessary and sufficient for the 2SLS to identify positively weighted sums of agent-specific effects of each treatment: average conditional monotonicity and no cross effects. Our identification analysis allows for any number of treatments, any number of continuous or discrete instruments, and the inclusion of covariates. We provide testable implications and present characterizations of choice behavior implied by our identification conditions.

Journal of Public Economics 217 Doi: https://doi.org/10.1016/j.jpubeco.2022.104788

Are politicians in power treated more leniently in court? We show that Brazilian mayoral candidates charged with misconduct are 65 percent less likely to be convicted if they narrowly win the election. Politicians play no direct role in the judges’ careers, suggesting that formal independence does not completely insulate the judiciary from political influence. The effect is driven by districts with few judges and by judges with higher career instability.

Economics Letters 215(110486) Doi: https://doi.org/10.1016/j.econlet.2022.110486

Recent literature raises concerns about monotonicity conditions required to interpret IV estimates under heterogeneous effects. A prominent example involves random decision-maker IV designs where decision-makers exhibit systematic differences in both preferences and skills. We develop tests of monotonicity in the context of judicial decision-making using proxies of judicial errors based on appeals and reversals of trial decisions from Norwegian court records. Our tests fail to reject average monotonicity. This suggests that differences in stringencies across judges are not sufficiently driven by skills to raise concerns about the validity of the random judge IV literature.