This thesis consists of four individual essays, and a joint introduction. The theme of these essays is interaction in and integration of regional labour markets. In view of this theme it is observed that economic activities are unevenly distributed across space. In the regional labour market workers’ supply of labour and firms’ demand for labour are matched. At the core of this thesis is the idea that the spatial structure of regions described, for example, by separation and accessibility measures, is important for the daily interaction pattern of workers and workplaces. Firms/workers all have a location, and given the associated spatial distribution, the accessibility to workers/workplaces differs between the locations. Consequently, analysis of spatial interaction aims at incorporating some form of spatial structure into the modelling framework. In the first essay, methods for identification of functional regions using commuting data are applied to Sweden in general and to the Fyrstad region in particular. In the second essay, a specific change in the commuting infrastructure is analysed. The possible effects on total wages earned, and the distribution of these benefits among classes of workers (identified by gender and education) are assessed. Essay number three examines whether in addition to differences in commuting behaviour between classes of workers there also exist regional variations. The fourth essay investigates barriers to commuting that can be associated with county borders.