title: From new entries to retirement: The changing age composition of the U.S. male labor force by industry.
abstract: The process whereby the age composition of an industry is formed appears to be largely a function of past rates of growth in employment; the social (or institutional) framework sets limits and affects the ensuing age composition but relatively little. The following types will illustrate this process. 1. Consider an industry which has increased considerably more rapidly in employment over several decades than has the total labor force. The rapid growth brings in a disproportionately large share of youth who are first entering the labor market; other younger workers move from slowly growing (or declining) industries. These movements add many more younger workers. On the other hand, there is little, if any, unemployment in the industry so that there are few pressures being exerted on the older workers to retire, and relatively few will retire. Under these circumstances the age composition will be younger than tliat of the entire male working force. 2. Consider an industry which has grown slowly, if at all, for some time. There will be comparatively fewer (in comparison with the first example) new entries and less mobility from other industries. The men already engaged in this industry will continue to work there; they gradually become older and are not counterbalanced by increasing numbers of young workers. Unemployment is likely to be higher, leading to a higher retirement rate. There are also likely to be large numbers of men a decade or two under the retirement age-the heritage of an "ancient" period when the industry had experienced significant increases in employment; these add pressure on the older men and more retire. The age composition of such an industry gradually veers toward the older side; it is considerably older than that of the entire male working force. At any given moment of time most industries will reflect variable past growth rates. For example, one industry may have a very large proportion of young workers because it grew very rapidly in employment only during the decade prior to the time of study (i.e., the time of a decennial census); another may have a large proportion in the middle ages reflecting very rapid growth two or three decades earlier, followed by very slow growth in the decade prior to the time of study; and so forth.In light of the foregoing analysis, it appears that technological change, as measured by average annual changes in output per worker, has little bearing on the age composition of an industry. Conversely, the latter probably does not affect changes in output per worker.
authors.affiliation: Bureau of Applied Social Research, Columbia University, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Jaffe