From the abstract of a
study done by Norma Coe and Matthew Rutledge for the Center for Retirement Research at Boston College:
Much as in previous recessions, the number of applications to public
disability insurance programs increased sharply during the Great
Recession. We find that the composition of applicants also changes
across business cycles. For example, applicants during economic
downturns, and especially during the Great Recession, are younger,
better educated, higher income, and more likely to have recent work
experience. However, we find only mixed evidence supporting the theory
that the increase in applications in downturns is caused by healthier
applicants who apply to disability programs only because they are
unemployed. ...
We find that changing demographics and unemployment rates explain less
than half of the increase in the application rate and only one quarter
of the increase in the awards to applicants (the allowance rate) between
the 2004-2006 expansion and the Great Recession. Further, these same
factors predict a fall in the award rate (among eligible individuals),
in contrast to the increase observed in the data. Together with the
fact that there have been no programmatic changes in the disability
programs in the 2000s, these results suggest there have been fundamental
changes over the last decade in the way that people apply to disability
and in the way these applications are evaluated that cannot be
explained by observable differences.
I have read through this report and do not see any explanation of the logic used by the authors in coming to the conclusion that there must have been some "fundamental change" in the last decade in the way that disability claims are evaluated. It is just stated baldly. The report indicates that the authors were, in general, considering demographic factors such as age but it's quite clear that their focus was on macroeconomic factors. In general, I'm just leery of a report by economists who has no real understanding of how disability is determined at Social Security.
In reports like this there is always the underlying assumption that working people with health problems sit around thinking about whether they should continue work or apply for Social Security disability benefits. I'm sure that some do but I'm also sure that's generally not the case. Only a few people stop work due to illness and then immediately file Social Security disability claims. The vast majority wait months, even years, to file disability claims. They hope they'll get better. They don't want to apply for Social Security disability benefits because they view it as difficult and unpleasant and an admission of a personal failing. Speedups and slowdowns in disability claims are primarily due to demographic factors but secondarily due to factors that increase or decrease the financial pressures faced by potential claimants who have already left employment. Often, potential claimants, that is people who have already left work due to illness, are motivated to file claims by the loss of some other family income, such as their spouse being laid off and their family being desperate for income. Almost always people stop work and only later start thinking about Social Security disability.