BACKGROUND The geographic proximity of parents and adult children is a key element of intergenerational solidarity. Many studies have identified geographical distance as an important determinant of intergenerational support: living nearby increases the amount of mutual support provided. It can, however, also be regarded as a dimension of intergenerational solidarity: the current degree of proximity is the result of past migration decisions made by both generations, in which present and future care demands potentially played a key role. OBJECTIVE We take this endogenous nature of geographical distance into account by examining theindirect effect of the determinants of the actual level of support through geographical distance. Both upward support (personal care provided to mother) and downward support (help with childcare received from mother) are considered. METHODS Path analyses are performed on data from the Generations and Gender Survey for France and Bulgaria using a general latent-variable modelling framework in multiple-group models. RESULTS In addition to strongly affecting the level of support provided and received, geographical distance itself is affected by several individual and family-related variables, which in turn have an indirect effect on the level of intergenerational support. The results suggest that proximity can be used as an adaptive strategy: e.g., working adult children in France receive more help with childcare because of their greater proximity to their mothers. Having a greater care need may have triggered this choice of residence. Similarly, single parents with no partner to rely on tend to live closer to their mothers, and therefore receive more help. CONCLUSIONS Geographic proximity can be considered a latent form of solidarity that functions as a mediator between background factors and manifest, functional solidarity.