This article studies the variables of entrepreneurship at the regional (countries) level proposed by the Global Entrepreneurship Monitor (GEM) in its periodic global reports. This response to the suggestions and concerns of various authors is related to the need to analyze the theoretical foundation of the variables used by GEM. The validity and reliability of GEM data for the scientific study of entrepreneurship are also analyzed. Finally, the potential of GEM data to manage entrepreneurship variables at the country level is studied. Data from the GEM global report and the fifty countries for which data are available on all variables are used in the study. The methodology used is the Rasch mathematical model, a valuable alternative to the Classical Theory of the Test. The results confirm the theoretical validity of GEM data, its validity and reliability for the development of scientific studies, and its potential for managing entrepreneurship variables at the country level. Both the methodology used and the conclusions obtained constitute novel contributions to this field.