Abstract Expressionism famously shifted the center of the advanced art world from Paris to New York. The triumph of Abstract Expressionism, and its subsequent abrupt decline in the face of Pop Art, are familiar tales in the literature of art history. Econometric analysis of evidence from auction markets now provides a basis for dating precisely the greatest innovations of the leading Abstract Expressionists, and of the leaders of the cohort that succeeded them. These data demonstrate how fundamentally each of these revolutions affected the nature of painting, by showing how greatly the creative life cycles of the experimental old masters of Abstract Expressionism differed from those of the conceptual young geniuses who followed them. The innovations of the Abstract Expressionists were based on extended experimentation, as they searched for novel visual images; Pop artists rejected this open-ended search for personal forms, and instead treated painting as the impersonal transcription of preconceived ideas. Accumulation of experience was critical for the Abstract Expressionists, who produced their most valuable art late in their lives, whereas lack of experience allowed the next generation the freedom to imagine radically new approaches, and they produced their most valuable art early in their careers.