Hans-Peter Kohler – författare

The central aim of many studies in population research and demography is to explain cause-effect relationships among variables or events. For decades, population scientists have concentrated their efforts on estimating the ‘causes of effects’ by applying standard cross-sectional and dynamic regression techniques, with regression coefficients routinely being understood as estimates of causal effects. The standard approach to infer the ‘effects of causes’ in natural sciences and in psychology is to conduct randomized experiments. In population studies, experimental designs are generally infeasible.

In population studies, most research is based on non-experimental designs (observational or survey designs) and rarely on quasi experiments or natural experiments. Using non-experimental designs to infer causal relationships—i.e. relationships that can ultimately inform policies or interventions—is a complex undertaking. Specifically, treatment effects can be inferred from non-experimental data with a counterfactual approach. In this counterfactual perspective, causal effects are defined as the difference between the potential outcome irrespective of whether or not an individual had received a certain treatment (or experienced a certain cause). The counterfactual approach to estimate effects of causes from quasi-experimental data or from observational studies was first proposed by Rubin in 1974 and further developed by James Heckman and others.

This book presents both theoretical contributions and empirical applications of the counterfactual approach to causal inference.

Fertility rates vary considerably across and within societies, and over time. Over the last three decades, social demographers have made remarkable progress in documenting these axes of variation, but theoretical models to explain family change and variation have lagged behind. At the same time, our sister disciplines—from cultural anthropology to social psychology to cognitive science and beyond—have made dramatic strides in understanding how social action works, and how bodies, brains, cultural contexts, and structural conditions are coordinated in that process. Understanding Family Change and Variation: Toward a Theory of Conjunctural Action argues that social demography must be reintegrated into the core of theory and research about the processes and mechanisms of social action, and proposes a framework through which that reintegration can occur. This framework posits that material and schematic structures profoundly shape the occurrence, frequency, and context of the vital events that constitute the object of social demography. Fertility and family behaviors are best understood as a function not just of individual traits, but of the structured contexts in which behavior occurs. This approach upends many assumptions in social demography, encouraging demographers to embrace the endogeneity of social life and to move beyond fruitless debates of structure versus culture, of agency versus structure, or of biology versus society.