Using information from the Encuesta nacional de ocupación y empleo (ENOE), income dif ferences between formal and informal workers in the northern border states of Mexico are analyzed. The ANOVA methodology suggests that the income of workers dif fers according to the type of employment (formal/informal), type of work, and interaction ef fect. The logit model shows that the likelihood of informal employment is associated with lower levels of education and the job search process.