Understanding the composition and magnitude of the enonnous economic burden injuries place on society remains a research issue, even though this subject has been under study for several decades. The human capital approach to measuring economic costs has evolved to the point where the methodology is widely accepted and many practical applications have been demonstrated. Most of the gaps in the state-of-knowledge of the human capital methodology concern problems of measurement, including estimating several sub-sets of the incidence, and problems in estimating the magnitude of some costs which are not collected routinely. The human capital method and certain of its derivitives are the primary method now used by the National Highway Traffic Safety Administration for determining economic costs resulting from injuries.

Another approach to measuring the economic impact of injuries, called willingness to pay, is being developed. This approach is concerned with value rather than cost, and is more directly applicable to cost/benefit analysis than is human capital. Significant measurement problems remain to be solved for the willingness to pay method, This method is not widely applied within the National Highway Traffic Safety Administration because this agency does not perform strict cost benefit analyses in its formal decision making process.

Neither the human capital nor the willingness to pay methods of economic analysis provide a measure of the overall impact to society resulting from injuries, which is a broader, inter-disciplinary problem, requiring considerably more development.