This chapter contains a brief discussion of seven empirical questions that have been analyzed using econometric models. As will become clear, these models are not straightforward regression models, but in one way or another they all amount to extensions. This is done on purpose to show how econometricians come up with new models whenever relevant. The discussion cannot follow the studies literally, but merely suggests topics which are of interest to econometricians and which involve a combination of a practical question, data and a model. The papers themselves contain much more detail, and the summaries here are only sketches of what is in them. The main focus is on the research question, on the data, and on the model used to answer the questions. There is almost no discussion of related literature as this can be found in the references cited in the papers. There are two macroeconomic studies, two marketing studies, one financial study, one on politics, and one on temperatures. These last two are included to indicate that other research areas can also consider econometric models to answer their questions.

Convergence between rich and poor countries

The question of whether poor and rich countries display convergence in per capita income levels has been a topic of much recent concern in applied economics and econometrics.