Do Judges Vary in Their Treatment of Race? David Abrams (U of Chicago) Marianne Bertrand (U of Chicago) Sendhil Mullainathan (Harvard) June 5, 2007

Research Questions Does the legal system discriminate? Does the legal system discriminate? Are African-Americans more likely to be incarcerated? Are African-Americans more likely to be incarcerated? Do they receive longer sentences? Do they receive longer sentences?

Standard Approach sentence ijt = α + βrace ijt + X ijt + ε ijt jail ijt = α + βrace ijt + X ijt + ε ijt Problem: Race is not randomly assigned, so betas may be biased due to unobservables! Problem: Race is not randomly assigned, so betas may be biased due to unobservables!

Our Approach Use random assignment of cases to judges to answer a related question: Do judges vary in their treatment of race? sentence ijt = α + βrace ijt + X ijt + Σδ j D j + Σγ j D j *race ijt + mo t + ε ijt Test for equality of the γ j

Why is this interesting? Large variance of sentencing disparities may have negative implications for perceptions of fairness of judicial system Large variance of sentencing disparities may have negative implications for perceptions of fairness of judicial system Could also help explain different findings in different studies Could also help explain different findings in different studies Legally important Legally important Would such variation violate constitutional rights? Would such variation violate constitutional rights? No State shall…deny to any person within its jurisdiction the equal protection of the laws. (14 th Amendment)

Objectives Test that cases are randomly assigned to judges Test that cases are randomly assigned to judges Establish counterfactual where judges don’t vary in treatment of race Establish counterfactual where judges don’t vary in treatment of race For Both: Use Monte Carlo Simulation For Both: Use Monte Carlo Simulation Allows for small cell sizes Allows for small cell sizes Allows for skewed Bernoulli variables Allows for skewed Bernoulli variables

Monte Carlo Simulation Use for both test of random assignment and heterogeneity in racial gap Use for both test of random assignment and heterogeneity in racial gap Create cells at the month level Create cells at the month level Simulate each observation 500 times, draw simulated data from same cell, with replacement. Simulate each observation 500 times, draw simulated data from same cell, with replacement. For inter-judge heterogeneity in racial gap in sentencing: For inter-judge heterogeneity in racial gap in sentencing: Create cells at the month-race level Create cells at the month-race level

Data Description-Chicago Data Circuit Court of Cook County Circuit Court of Cook County Largest unified court system in the country Largest unified court system in the country Main Chicago location handles 85% of cases Main Chicago location handles 85% of cases Assignment procedure: Assignment procedure: Daily assignment of cases uses random number generator Daily assignment of cases uses random number generator Exceptions include drugs, murder, some sex crimes Exceptions include drugs, murder, some sex crimes Suburban court locations perform their own random assignment Suburban court locations perform their own random assignment Data includes all felony cases from Data includes all felony cases from Over 500,000 cases Over 500,000 cases Includes charge(s), judge(s), defendant characteristics, plea, disposition, sentence Includes charge(s), judge(s), defendant characteristics, plea, disposition, sentence We use small subset of the data We use small subset of the data

Case Characteristics

Case types and outcomes

Bootstrapping (I) Testing for Random Assignment

25%75% 25%75%

Random Assignment Checks Race Race Gender Gender Age Age Total Number of Charges Total Number of Charges Charge Type Charge Type Also use 10%-90% and 5%-95% ranges Also use 10%-90% and 5%-95% ranges

Bootstrapping (II) Testing for Racial gap Heterogeneity

Numerical Implications How much does the sentencing gap between black and white defendants vary across judges? How much does the sentencing gap between black and white defendants vary across judges? Judge Percentile shift Change in Incarceration Gap Change in Sentence Length (months) 25%-75% %-90%.1810

Robustness Check Perhaps race is a proxy for other characteristics, (such as charge) that receive heterogeneous treatment by judges. Perhaps race is a proxy for other characteristics, (such as charge) that receive heterogeneous treatment by judges. Address this concern by looking at subsets of the data Address this concern by looking at subsets of the data Drug crimes Drug crimes EFT EFT Violent Violent Other Other

Interpretations Evidence of “too much heterogeneity” in Chicago incarceration data need not imply discrimination against Blacks. Suppose the “appropriate” gap is 25% Suppose the “appropriate” gap is 25% Variation in judges between 15 and 25% would be a sign of reverse discrimination Variation in judges between 15 and 25% would be a sign of reverse discrimination Possible approaches to deal with this issue in the future: Possible approaches to deal with this issue in the future: Recidivism? Recidivism?

Focus on Restricted Sample Eliminate “drug” judges Eliminate “drug” judges 8 judges receive only drug cases 8 judges receive only drug cases Overflow drug cases are randomized among remaining judges Overflow drug cases are randomized among remaining judges Keep only central location Keep only central location Can expand to other locations, but central location accounts for 85% of cases Can expand to other locations, but central location accounts for 85% of cases Restrict to initial appearance of defendant Restrict to initial appearance of defendant Subsequent appearances often assigned to the same judge Subsequent appearances often assigned to the same judge Restrict to judges known to have been regular judges under current judicial administration (through consultation with presiding judge’s office) Restrict to judges known to have been regular judges under current judicial administration (through consultation with presiding judge’s office)