The role of research and statistics in the development of Social Security.
D004185:Disability Evaluation; D004608:Eligibility Determination / Q000639:trends; D005380:Financing, Government / Q000639:trends; D006801:Humans; D012106:Research; D012943:Social Security / Q000331:legislation & jurisprudence / Q000458:organization & administration; D013223:Statistics as Topic; D014481:United States