The Cumulative Data File consists of variables derived from the 1948-2016 series of biennial ("time-series") SRC/CPS National Election Studies. To produce this dataset, cross-section cases from the time-series election studies have been pooled. The total unweighted cross-section N is 59,944.
A variable in the dataset almost always represents a question which has been asked in three or more (time-series) studies. This dataset incorporates, for specific questions, data from all the time-series studies in which the question was asked in comparable fashion.