The present work evaluates an unforeseen effect on Mexico of the Simpson-Rodino Law of 1986: The expansión of the pool of legal Mexican commuter workers to the United States. The analysis of the law's impact on this labor sector (consisting of workers resi- ding in the northern Mexican border zone who are legally and regularly employed in the United States) in terms of numbers of workers, age, sex, education, family structure and location of residence is based on information generated for the state of Baja California through the Demographic Surveys of 1986 and 1990.Using these data and LOGIT regression models, which include variables related to individuals as well as their household members and their context, statistical evidence is generated in support of the propositions that, i) and expansión ocurred of the spectrum of social strata incurring in this type of migration; ii) the selectivity characteristics of new entrants into this migration group show a reproduction strategy oriented toward upward mobility; and iii) contextual factors led to a geographic redistribution of the commuter migrant group in the state of Baja California.