A 2014 study in the "Journal of Political Economy" found that 9% of the black-white gap in sentencing could not be accounted for. The elimination of unexplained sentencing disparities would reduce "the level of black men who are in federal prisons by 8,000–11,000 men of a black male prison population of 95,000 and save $230–$320 million in direct costs per year." The majority of the unexplained sentencing disparity appears to occur at the point when prosecutors decide to bring charges which carry "mandatory minimum" sentences. A 2018 paper by Alma Cohen and Crystal Yang of Harvard Law School found "that Republican-appointed judges give substantially longer prison sentences to black offenders versus observably similar non-black offenders compared to Democratic-appointed judges who serve within the same district court." A 2018 study in the "Quarterly Journal of Economics" found that bail judges in Miami and Philadelphia were racially biased against black defendants, because white defendants had higher rates of pretrial misconduct than black defendants did.