This paper introduces a growth framework with endogenous industry creation and life-cycles to analyze the relationship between industry dynamics and aggregate growth. The model achieves steady aggregate growth while new industries continually emerge and existing ones gradually slow down, resulting in ongoing evolution of the economy’s industrial composition. Despite its simplicity, the framework replicates key life-cycle patterns documented in the literature and allows for broad applications. The quantitative version of the model suggests: (1) the growth rate exhibits a U-shaped relationship with the startup entry rate; (2) fiercer within-industry competition fosters variety creation; and (3) innovation policies that support variety creation may be more effective than those subsidizing incumbent R&D investment.