Louis Henry Research Paper

Henry intended to go beyond the mere measurement of phenomena, and undertook to decompose reproductive processes into their component factors, what later became known as the proximate determinants of fertility. He decided to study the ‘physiological’ level of fertility, that is, the fertility that would prevail among married women or couples in the absence of deliberate efforts to limit their number of births; this he called ‘natural’ fertility. In a contemporary population, however, contraception and abortion that are subject to human decisions are widespread, and it becomes difficult to investigate physiological factors. In his quest to find reliable data on populations where family limitation was not practiced, Henry studied records from the European past, at a time when the recording of vital events was complete and accurate. He first used a series of genealogies on the ruling classes of Geneva, going all the way to the sixteenth century (Henry 1956); later he analyzed the parish records for a village of Normandy, Crulai, that had been extensively compiled by a local historian, Etienne Gautier (Gautier and Henry 1958). The records for Geneva demonstrated the sharp contrast between the earliest marriage cohorts, where marital fertility by age seemed to be independent from age at marriage, and the later cohorts where the behavior of couples was clearly modified by the duration of their marriage and the number of children they had attained. It could be shown conclusively that the bourgeoisie of Geneva had adopted family limitation as early as the second half of the seventeenth century. In contrast until the end of the eighteenth century, Crulai, the first parish analyzed by the new method of family reconstitution that Henry had invented, showed the features of a regime of natural fertility, where parity does not affect a woman’s subsequent behavior.

In a manual written with Michel Fleury (Fleury and Henry 1956), he laid out—to the minutest details—the rules for the processing of parish data. These rules have been followed faithfully by demographic historians, not only in France but also in other European countries such as England, where they guided the work of the Cambridge Group for the History of Population and Social Structure, and in Canada. Henry would publish another textbook on historical demography (Henry 1967). Moreover, applying the vast experience accumulated in his early parish studies, he initiated a study of rural France, using a representative sample of French parishes during the eighteenth century. He analyzed this material by aggregative methods, and for a smaller sample of parishes used nominal information to reconstitute families. The project provided the first national series of estimates of fertility, mortality, and nuptiality for a Western European country in the eighteenth century. This body of work makes Louis Henry the uncontested father of historical demography as it is practiced today.

Mining the past for data on populations that did not consciously limit their family size was initially only a tool towards measuring the physiological components of human reproduction. Henry identified the factors to be considered as fecondability, the probability that a conception would result in a live birth; the delay in the resumption of ovulation after a delivery or nonsusceptible period, and total or partial sterility. He provided estimates of the value of these parameters on the basis of his own historical studies of population, but also of various accurate measurements made on other selected populations. His work was picked up by English and American demographers and biometricians working on fertility models, and among them by Mendel Sheps and Jane Menken who edited a collection of translations from Henry’s most important articles (Henry 1972.) The seminal importance of Henry’s work was acknowledged by the Population Association of America when it made him the first recipient of the Irene B. Taeuber Award for Excellence in Demographic Research in 1977. Just before his death in 1991, the International Union for the Scientific Study of Population had named him its first Laureate.

The concept of natural fertility is often considered as one of Henry’s most significant contributions to population studies. He did not invent the term, but he defined it rigorously and provided means to identify natural fertility regimes. It refers specifically to the behavior of married couples, and is therefore not affected by variations in the proportions married and the age at marriage. Natural fertility is compatible with behavior that may affect the levels of natural fertility (frequency of intercourse, length of breast feeding) or even with attempts to space birth that are not depending on parity. Although the notion remains controversial, it has been used widely in the study of the fertility transition, both in the West and in today’s developing countries.

Bibliography:

1. Fleury M, Henry L 1956 Des registres paroissiaux a l’histoire de la population. Manuel de depouillement et d’exploitation de l’etat civil ancien. INED, Paris
2. Gautier E, Henry L 1958 La population de Crulai, paroisse normande. Etude historique. Presses universitaires de France, Paris
3. Henry L 1953 Fecondite des mariages. Nou elle methode de mesure. Presses universitaires de France, Paris
4. Henry L 1956 Anciennes familles gene oises. Etude demographique, XVIe–XXe siecle. Presses universitaires de France, Paris
5. Henry L 1967 Manuel de demographie historique. Droz, Geneva, Switzerland
6. Henry L 1972 On the Measurement of Human Fertility. Selected Writings of Louis Henry. Elsevier, New York