This study examines the factors that contribute to student learning outcomes in Argentina, using data from PISA for years 2000, 2006, 2009, and 2012. We estimate a year-specific production function whose results are then used to explain the trends in learning outcomes in terms of changes in inputs and changes in parameters linked to each of them (the _efficiency effect_ ). The paper is organized as follows: Section II presents a brief review of the literature. Section III describes the trends in learning outcomes using four rounds of PISA: 2000, 2006, 2009, and 2012. Section IV presents the methodology, including the education production function and the microsimulation used to decompose the changes in learning outcomes in terms of inputs, parameters, and residuals. Section V presents the findings. Finally, Section VI offers reflections on implications for education policy in Argentina.

# **II. Literature Review**

Learning is a complex, multi-faceted process. There are two types of factors that influence learning: those that are endogenous to the education system, that is, within the sphere of influence of education policy makers, and those that are exogenous, or beyond the sphere. This section cites some of the conventional exogenous factors identified by the literature and briefly summarizes the evidence on endogenous inputs, dividing them into two broad groups: school characteristics and institutional setting.

The evidence linking learning outcomes with exogenous factors such as socioeconomic background and individual characteristics is vast (Coleman et al., 1966, Lee and Barro, 1997, Fertig and Schmidt, 2002, and many others). There is some evidence that, in general, socioeconomic status is one of the most important determinants of learning outcomes (Mizala, Romaguera, and Urquiola, 2007, and others) but relatively less important than school factors in developing countries (Heyneman and Loxley, 1983, Fuller, 1987, Baker, Goesling, and Letendre, 2002, and others). With regard to parents’ education, the literature also points to this factor as being correlated with student achievement and highly correlated with grade attainment in developing countries (Aturupane, Glewwe, and Wisniewski, 2007), particularly in the case of the mother’s education (Glewwe and Jacoby, 1994, Glick, Randrianarisoa, and Sahn, 2011). There is overwhelming evidence that family background has a stronger effect on achievement in reading than in math and science (Fuchs and Wößmann, 2004).

Evidence from the United States shows that the home environment has a special impact in a child’s early years, leading to student academic success later (Carneiro and Heckman, 2004). For developing countries, a longitudinal analysis of determinants of learning in 27 countries finds that homes that had more books available were correlated with children who performed better in school (Evans et al., 2010), a finding consistent with previous investigations of the presence of books in the house (Fuchs and Wößmann, 2004, and Yayan and Berberoglu, 2004). This is also corroborated by data from PISA, looking at 20 OECD countries, where students with more books in the home had an educational advantage over students with fewer (Thompson and Johnston, 2006). Other elements of the home environment that have seemed to impact cognitive outcomes in children are the existence of opportunities for learning, the warmth of mother-child interactions, and the physical conditions of the home (Brooks-Gunn and Duncan, 1997, and Majopribanks, 1994).

In terms of student characteristics, looking across all OECD countries, girls outperformed boys by 38 points (an average of one year) in reading (OECD, 2014). For math, boys outperformed girls by 11 points (an average of three months). Another student characteristic that is an important 3