Event-Centered Demographic Methods: Theory and Examples

New general event-centered demographic concepts are introduced that provide a generalization of reduced events and event-history methods. They provide a general way of defining indicators where every event contributes to the phenomenon of interest. The basic concepts that apply to all event-centered measures are defined, including the processes of reduction and aggregation. Reduction requires the precise location of an event in a Lexis space, and a reduction factor against which the event is measured up. Different reduction factors lead to different indicators. Aggregation defines summary measures of reduced events. Special attention is paid to birth cohort size as a reduction factor. The indicators are the result of concurrent phenomena like mortality, fertility and migration without requirinng their previous isolation. Exposure-based reduction factors lead to standard demographic indicators such as age-specific rates or the TFR. . Period and cohort examples of reduced birth and death measures are provided, such as the Birth Replacement Sum or the Death Cohort. All the concepts are defined at the event level, and can be estimated from vital registration microdata, aggregate data or survey microdata. The concepts are illustrated with examples of application, and are connected to alternative aggregate estimates and ratios.