quality is an important factor since it is directly related to the capacity of the educational system to impact the life opportunities of the population (Blanco, 2011). It has been documented that inequalities in learning outcomes are associated with the type of school attended. For example, according to Saravi (2009), at secondary level of education, private schools have performed better and, among the public schools, those of a general modality ( _secundarias generales_ ) have better results.

Although the coexistence and interrelation of ascribed factors and education in the occupational attainment process concur with evidence from international findings, in the case of Mexico, research results have suggested that the effect of schooling on occupational attainment may be declining in recent decades, while the effects of the other ascribed factors are increasing (Puga and Solís, 2010; Solís, 2007). This further demonstrates the increase in the inequality of opportunities and the rigidity of national social mobility.

The most recent studies of intergenerational mobility at a national level have confirmed the rigidity of the Mexican social stratification. Mexican society is characterized by high rates of social mobility in the middle sectors, but high levels of persistence for both the upper and lower sectors, which contributes to the reproduction of wealth and poverty. Individuals face difficulties moving to different social stratums than the one they were born into. It is extremely hard to experience long-distance changes (for example, having a father who is an agricultural worker and becoming a non-manual professional, which represent extremes of the occupational hierarchy) or to cross the existing barrier between the rural and urban sectors (Torche, 2010; CEEY, 2013; Solís, 2016).<sup>10</sup> Furthermore, inequalities between men and women have been documented. Notwithstanding females experience a greater upward mobility, in comparison to males, those born into the lowest strata remain more frequently in lower positions, while the females with origin in the higher strata tend more to experience downward mobility (CEEY, 2013).

This rigidity not only characterizes the intergenerational mobility of individuals, but also that of the territories. Cortés and Vargas (2017), based on analysis of the evolution of the municipalities in Mexico between 1990 and 2015, identified a tendency of immobility in municipal marginalization levels. Valdés and Vargas (2018) confirmed this pattern of immobility analyzing the evolution of the municipal social backwardness between 2000 and 2015.

Even within this adverse context, PROSPERA has been able to contribute to well-being improvement of its beneficiaries. It has been documented that the program has had positive impacts on different human capital indicators.<sup>11</sup> In the education area, of specific relevance for this study, PROSPERA has reduced school dropout rates for youths from rural localities, and has improved early enrollment to school, transition from primary to secondary school, and consecutive grade progression, as well as the number of years of schooling received (Parker, 2005; Parker, Behrman and Todd, 2005; Todd et. al., 2005; Parker and Behrman, 2008). Other

> 10 In comparative terms, it has lesser social fluidity than countries such as Sweden, United States, Brazil and Chile (Torche, 2010).

> 11 The number of studies documenting impacts on human capital is very large. The following are summaries of such impacts in different historic moments of the program, IFRI (2000), Cruz, de la Torre and Velázquez (2006), Campos (2010) and Parker and Todd (2017).

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