Socio-demographic variables. Among the socio-demographic data collected during the
interviews, three variables were taken into account for this study: age, gender, and educational
level. Four age groups were defined: 20–29, 30–39, 40–49 and 50 and over. Gender was coded
as follows: 1 for women, 0 for men. Five levels of education were defined, in accordance with to
the Senegalese school system: none, primary (1 to 5 years ofschooling) intermediate (6–8
years), secondary (9–12 years), university (13 years and over).