Megan Stevenson has posted Distortion of Justice: How the Inability to Pay Bail Affects Case Outcomes on SSRN.
Here is the abstract:
Instrumenting for detention status with the bail-setting propensities of rotating magistrates I find that pretrial detention leads to a 13% increase in the likelihood of being convicted, an effect explained by an increase in guilty pleas among defendants who otherwise would have been acquitted or had their charges dropped. On average, those detained will be liable for $128 more in court fees and will receive incarceration sentences that are almost five months longer. Effects can be seen in both misdemeanor and felony cases, across age and race, and appear particularly large for first or second time arrestees. Case types where evidence tends to be weaker also show pronounced effects: a 30% increase in pleading guilty and an additional 18 months in the incarceration sentence. While previous research has shown correlations between pretrial detention and unfavorable case outcomes, this paper is the first to use a quasi-experimental research design to show that the relationship is causal.