In French border regions, the unemployment durations of communes increase with distance from the border to a threshold of about thirty kilometres, then slightly decrease after this threshold. Depending on the definition of exit from unemployment, differences in unemployment durations between border communes and those located around thirty kilometres from the border are one to eight months, while controlling for the labour force composition. In order to explain this "border effect", we first use a spatial autoregressive model estimated by maximum likelihood. Then we calculate residual durations of unemployment using a linear model estimated by ordinary least squares. The advantage of living near the border is mainly due to certain effects of social composition, especially the proportion of cross-border workers, who improve the quality of informational and relational networks. This scenario applies to communes close to Belgium, Luxembourg, Switzerland and Spain, but it seems less effectual near the borders with Germany and Italy.