Our first task in this final chapter is to summarize the main conclusions of Chapters 1 through 11. This task will occupy us in Section 12.1. Then in Sections 12.2 and 12.3 we shall discuss, in a tone more subjective and speculative than in the rest of the book, the human costs of shift-work and the public-policy issues raised by our general subject.

Summary of findings and conclusions

The conclusions will be listed under the headings of methodological issues, substantive findings on the determinants of shift-work, and the productive and distributive effects of shift-work. With the exception of statements 3, 4, 10, and 17, which apply to shift-work exclusively, all of the following conclusions are applicable to both shift-work and capital utilization.

Methodological issues

1. According to economic theory, shift-work is both cause and consequence of capital intensity. On the consequence side, this statement has been part of conventional wisdom for a long time; the causal aspect was pointed out first by Marris (1964). The following implication of the statement, however, has not been widely appreciated: Observed correlations between capital intensity and shift-work do not provide empirical confirmation that capital intensity is a cause of shift-work.

2. Shift-work may be both cause and consequence of scale. Shift-work is always a cause of large scale in the sense that the undertaking of shift-work causes total factory output to be larger than it would otherwise be.