In recent years, most European countries have experienced substantial demographic changes and rising cultural diversity. Understanding the social and economic impacts of these shifts is a major challenge for policymakers. Richard Florida’s ideas have provided a popular – and pervasive – framework for doing so. This paper assess Florida’s legacy and sets out a ‘post-Florida’ framework for ‘technology, talent and tolerance’ research. The paper first traces the development of Florida’s ideas. ‘Florida 1.0’, encapsulated by the Three Ts framework, has performed badly in practice. There are problems in bringing causality to the fundamental relationships, and in consistently replicating the results in other countries. ‘Florida 2.0’, though suggests that Creative Class metrics have value as alternative measures of human capital. This create space for a post-Florida agenda based on economic micro-foundations. I argue that the growing body of ‘economics of diversity’ research meets these conditions, and review theory and empirics. Urban ‘diversity shocks’ shift the size and composition of populations and workforces, with impacts operating via labour markets, and through wider production and consumption networks. While short-term labour market effects are small, over time low-value industrial sectors may become migrant-dependent. Diversity may help raise productivity and wages through innovation, entrepreneurship, market access and trade channels. Bigger, more diverse cities help generate hybridised goods and services, but may also raise local costs through crowding. All of this presents new challenges for policymakers, who need to manage diversity’s net effects, and address both economic costs and benefits.