Our knowledge of the institutional features of local government in Canadian cities is surprisingly fragmentary. The academic literature has long identified dominant tendencies in Canadian local institutions, but systematic empirical data has been missing. In this article, we address this gap in knowledge in two ways. We introduce the Canadian Municipal Attributes Portal (CMAP), a new open-access database that contains information on dozens of institutional features of local government for nearly 100 of the most populous municipalities in Canada. We then propose a new multidimensional index of authority concentration, which is designed to capture variation in the local structure of decision-making authority in a systematic and nuanced manner. We apply this index to a systematic pan-Canadian subsample of 65 CMAP municipalities. The result is a rich portrait of institutional variety, one that both corroborates and substantially extends our current understanding of the shape of municipal institutions in Canadian cities.
