We develop a tractable dynamic model of productivity growth and technology spillovers that is consistent with the … emergence of real world empirical productivity distributions. Firms can improve productivity by engaging in in-house R\&D, or …-growth equilibrium featuring persistent productivity differences even when starting from ex-ante identical firms. The long …

. Economic growth (growth of real GDP) results from growth in the quantity and productivity of polluting intermediates. Pollution … implies that the rate of GDP growth remains below productivity growth (deceleration). While neither green innovation nor …