'Economic well-being' is appearing as the high-level goal of regional economic development and other legislation around the world, including the Local Government Act 2002 in New Zealand. This term is, however, rarely if ever defined. The purpose of this paper is to explore the economic literature to explore how the term can be interpreted by policymakers and practitioners. The first strand reviewed comes from development economics, especially drawing on Sen's concept of development as freedom. The second strand reviewed comes from the sustainability literature, beginning with the Bruntland Commission in 1987. The paper draws on Solow's definition of sustainability as 'non-declining per capita human well-being over time'. This leads to a discussion of the central role of maintaining five different types of capital: human-made, social, natural/environmental, cultural and human capital. The paper concludes with a discussion of how it can be operationalised by practitioners in their particular local circumstances.