traditionally, the public sector was the sole responsible for the citizen’s welfare. in recent years, a new tendency has begun to spread towards public and private collaborative models, in which said responsibility is shared. we center on these models to revitalize cities since they are developing important innovations. in the face of the lack of academic study in the latin languages, this work presents these models, reflecting critically on them to conclude proposing future research lines. among the conclusions, we can highlight the need of a change in the existing preconceptions about the obligations of private institutions regarding the society.