This overview shows the change in health care costs in the aggregate, as a share of GDP, and—along with other programs—the share of entitlements in the federal budget. These trends are unsustainable. Many current proposals for reform imply a one-time downward shift in the curve but do not...

It is argued that most econometric models are nonparametric and that parameterizations should typicall y be viewed as approximations made for purposes of estimation. These parameterizations should not be used to judge identification when the y are not a precise representation of prior...