Assessing the Contribution of the Deinstitutionalization of the Mentally Ill to Growth in the U.S. Incarceration Rate

We assess the degree to which the mentally ill who would have been in mental hospitals in years past have been trans‐institutionalized into prisons and jails. We also assess the contribution of deinstitutionalization to growth in the U.S. prison population. We find no evidence of trans‐institutionalization for any demographic groups for the period between 1950 and 1980. However, for the twenty‐year period from 1980 to 2000, we find significant trans‐institutionalization rates for all men and women, with a relatively large trans‐institutionalization rate for men in comparison to women, and the largest trans‐institutionalization rate observed for white men. Our estimates suggest that between 4 and 7 percent of incarceration growth between 1980 and 2000 is attributable to deinstitutionalization. While this is a relatively small contribution to prison growth overall, the results do suggest that a sizable portion of the mentally ill behind bars would not have been incarcerated in years past. We thank the Russell Sage Foundation for their generous support of this research.