Labour market regulation is a controversial area of public policy in both developed and developing countries. Mainstream economic analysis traditionally portrays legal interventions providing for minimum wages, unemployment insurance and (often only a modicum of) employment protection as ‘luxuries’ developing countries cannot afford. After decades of de-regulatory advice, international financial institutions have recently come to a less extreme position. But any such concessions to labour regulation are based on concerns for social stability or for short-term support to aggregate demand, while regulation continues to be viewed as harmful to economic efficiency in the long run. In this chapter, we take a deeper look at the impact of labour institutions on economic development in two ways. First, we propose a macroeconomic model of a balance-of-payments constrained “small” developing country open to trade and foreign capital. This helps us clarify the importance of a dynamic view of economic efficiency, as opposed to the static view embedded in mainstream policy advice. Secondly, we discuss the political economy of labour regulation. We argue that labour institutions promote economic development through positive effects on aggregate demand, labour productivity and technology.