Individuals Writ Large: An Epilogue on the “Ecological Fallacy”

Abstract

For more than three decades, social scientists have struggled with the statistical consequences of aggregation. Ever since Robinson (1950) first shocked a whole generation of social scientists with his demonstration of the “ecological fallacy,” much has been written about alleged fallacies, biases, pitfalls, and hazards of one kind or another lurking behind aggregate data and about strategies for circumventing them (Goodman, 1953, 1959; Blalock 1964; Scheuch 1966; Alker 1969; Shively 1969, 1974; Hannan 1971; Hammond 1973; Meckstroth 1974; Hanushek, Jackson, and Kain 1974; Hannan and Burstein 1974; Irwin and Lichtman 1976; Smith 1977; Langbein and Lichtman 1978). Intrigued—or alarmed—by the recurrent observation that correlations and regressions based on aggregate data (group means) often differ dramatically from those based on individual data, researchers have sought to answer the traditional question of ecological analysis: under what conditions can inferences to individual-level (micro) relationships be made from group-level (macro) data?