A problem that sometimes arises when the number of parameters increases in tandem with the number of observations. For example, models for panel studies may include individual-specific fixed intercepts, called “incidental parameters”, in addition to the “structural parameters” of interest, making the number of parameters tend to infinity as the number of individuals tends to infinity. In some models, such as logistic models with individual-specific fixed intercepts, this leads to inconsistent maximum like- lihood estimates of the structural parameters.