Abstract A model is presented in which social ties between individuals and private contributions to a local public good are interrelated. Ties are formalized by means of utility interdependence, and depend on the history of social interaction, in this case the joint provision of the public good. The resulting dynamic model generates equilibrium values of the intensity of ties and the private provision level. The impact of public provision on these variables is analyzed. Our results are very different from those obtained with the standard model, where individuals are only interested in the utility from own consumption.