We are our memory: A flexible framework for quantifying the demographic imprints of the past

Populations have demographic connections to history: people who were exposed to the past may still be alive or may at least have living kin. Denton and Spencer (2021) and Alburez-Gutierrez (2022) have articulated the concept of “demographic memory” to refer to how the memory of single events lingers in populations through their age or kinship structure. This article works to clarify and further demonstrate the usefulness of this concept. Theoretically, it argues for demographic memory as an idea that unifies and makes rigorously quantifiable many of the scattered ideas of historical embeddedness that exist across the social and biological sciences, including in economics, epidemiology, political science, and genetics. Methodologically, this article offers a flexible and widely applicable model of demographic memory defined by cohort survivorship. This model can estimate the memory of events, eras, and continuously varying conditions of interest, such as socioeconomic, political, and environmental variables, and it allows for social stratification in both the conditions of interest and how they are forgotten. As a proof of concept, this new model is applied to the memory of recent prime ministers in the United Kingdom and the memory of liberal democracy across the world.