Why Has the Social Security Disability Insurance Program Grown So Rapidly? Basically three reasons: (1) The aging of the workforce -- More people are working longer, and older people are more likely to qualify for disability; (2) More women than ever are working and, therefore, potentially eligible for disability, leading to higher numbers of disabled beneficiaries; (3) the 1984 changes in policy expanded the ways in which people could qualify for the disability program. See page 7 of the report.

Note that the non-partisan Congressional Budget Office says nowhere that people are using disability claims as an quasi-unemployment payment. That's because it just ain't so.