Social Security Disability Insurance (SSDI) applications and receipts vary greatly by state (McVicar 2006; Bound and Burkhauser 1999; Rupp and Stapleton 1998), which has led to concerns about potential inconsistencies in the application of disability standards. This possibility has prompted numerous Congressional hearings and reports and led the Social Security Advisory Board (2001a; 2001b) to express concern about the Social Security Administration’s (SSA) ability to disentangle the potential causes.
Much of the previous work focuses on the SSDI rolls, allowance rates or award rates; not as much attention has been paid to application rates (also referred to as filing rates) since Rupp and Stapleton (1998) summarized the known factors affecting caseloads.
Work by the Social Security Administration (SSA 1988) finds that economic and demographic differences are significant factors in explaining state SSDI application rates, but their sample lacks information about the underlying health of the population. Strand (2002) advances this work by adding some, albeit limited, health and health insurance information but also covers a very short time period (1997-1999). Duggan and Imberman (2009) explore the relationship between applications and the unemployment rate but do not control for other potentially confounding factors.