The fiscal impact of population change: discussion

It is now well established that world-wide demographic shifts are going to affect both the U. S. and world economies in ways that are not entirely predictable. What we can do--and what Ronald Lee and Ryan Edwards do so well--is to plot out for the future some of the fiscal implications under reasonable guesses about demographic, economic, and legal factors. These factors include what we know already from the past, such as the maximum number of people in the world of any age over 0 next year and over 10 in another ten years. A typical next step is to posit what in estimating circles is known as \\"current law\\" (defined partly by convention, not just law). Even if that law cannot possibly be maintained, some of its implications can be understood. Finally, one assumes some reasonable parameters, such as future fertility, mortality, and labor force participation, largely based on historical trends.