Insurance effects on US medical spending (1960-1993).

Regression results show that nearly half of 1960-1993 growth in real per capita medical spending and almost two-thirds of its 1983-1993 growth were due to ever-increasing levels of insurance coverage (the spending portion paid by third parties). Growth in coverage may have played a minor part as well; we would not rule out the standard finding that it has had a positive but relatively small effect. Viewed from a different perspective, the results imply that about two-thirds of 1960-1993 spending growth came via cost-increasing advances in medical technology resulting from: (1) commercial research and development induced by coverage levels and (2) noncommercial medical research. The remaining one-third, was due to standard factors: age-sex mix changes, income growth and coverage growth (the latter playing a small but indeterminate part).