Marc Patrick Brag Klemp, University of Copenhagen: "Empirical Investigations in Unified Growth Theory"

"Empirical Investigations in Unified Growth Theory"


Based on the use of a vast historical database of English church book records, the first paper documents that individuals born during the English famine in 1727–1728 were affected by increased mortality throughout life. This effect was strongest among the poorest families.

In the second paper, the data are combined with estimates of income, and it is documented that higher income had a negative causal effect on the intervals between births in England before the demographic transition. The effect appears to arise from deliberate actions.

The third paper is based on the same data and shows that children of couples with long intervals from their marriage to their first birth (and thus low fecundity and small families) were more likely to become literate and employed in a skilled profession. The paper thereby documents a negative causal effect of family size on the education of children.

The fourth paper is based on a similar and more comprehensive database from pre-industrial Quebec and establishes that individuals of intermediate fecundity (and thus an intermediate number of children) produced more descendants after two or more generations than individuals of high or low fecundity. In the light of the heritability of fecundity, the finding suggests that the forces of natural selection generated an evolutionary advantage for individuals characterized by an intermediate level of fecundity, raising their representation in the population.