Psychiatrists' distribution across the 50 states, 1978.

In 1978, both psychiatrists and a nonmedical professional group (lawyers) were more abundant in more populous, urbanized states. Lawyer-population ratios, however, correlated more strongly with the population's wealth; psychiatrist-population ratios correlated more strongly with the percentage of state population with college education and with state-mandated private insurance coverage of psychiatric services (both probable indexes of market demand). Even after controlling for population size and education, state-mandated insurance coverage was significantly related to the abundance of psychiatrist. Moreover, mandating states increased their psychiatrist-population ratios 100% faster after mandating coverage, whereas nonmandating states increased their ratios only 25% faster in comparable periods. While we investigate psychiatrists' geographic distribution, public policy formation can be aided if we also seek better measures of access and barriers to psychiatric care.