rather surprisingly suggest an increment of about 10 percentage points during the conflict period compared with the 2010 rate of 26%.<sup>36</sup> We build in this increment over 2010‐2015, applying the same enrollment rate for men and women, and keep it unchanged thereafter. Primary school duration is assumed to be 6 years (6‐11 years), secondary school, 6 years (12‐17 years), and university 4 years (18‐21 years). In Appendix 3, we provide further details on how we arrive at the average years of schooling in 2018.

By using the above methodology, we constrain changes to the national average of schooling years to arise from shifts in the distribution of the total population by age and gender, and in enrollment ratios. Because we use past composite values of average years of schooling, we do not consider changes in completion rates (that is, we are assuming completion rates are unchanged). This approach also does not consider other types of heterogeneity in educational attainment, for instance, that may depend on the socioeconomic status or geographical origination of migrants and conflict victims. Verme et al. (2016), focusing on the profile of refugees in Jordan and Lebanon, find that Syrian refugees in fact tend to have slightly lower levels of educational attainment than pre‐conflict Syrians.<sup>37</sup> To obtain human capital growth, we continue to assume the same calculations as in PWT 9 for the returns to education. Our calculations for the central projection using UN population statistics suggest that average years of schooling would have declined by 1.467 years for the population aged 15‐64 with human capital contracting by an annual average growth of ‐2.59% over 2011‐2015 and ‐ 0.56% over 2016‐2018 respectively. When we consider the additional decline of 1.8 million in the Syrian population discussed in the previous section, average years of schooling declines only marginally more, that is by 1.499 years. If we split this decline over time following the proportions in the first case, we obtain annual average growth rates in human capital of ‐2.64% over 2011‐2015 and ‐0.57% over 2016‐2018 respectively.

# _3.1.4 TFP_

The Conference Board estimates an average TFP growth of ‐9.5% over 2011‐2017 (from a low of ‐ 22.9% in 2012 rising to 2.8% in 2017). However, while the loss of TFP would be an important driver of loss in GDP potential, it could be that this high number reflects an underestimation of the destruction of physical and human capital.

Thus, as an alternative to The Conference Board’s calculations of TFP growth, we utilize Kim and Loayza’s (2019) model of determining TFP growth. The key element that feeds into this model is an overall index of TFP determinants, the determinants being education, infrastructure, innovation, institutions, and market efficiency. The composite index stood at 30.33 for Syria in 2010 on a scale between 1 and 100. We estimate the trajectory of this index over 2011‐2018 by calibrating its subcomponents. For the education index, we calculate a decline that is proportionate to the fall in average years of schooling of the working‐age population. Given that enrollment rates fall, and the exodus of Syrians increases noticeably only from 2013, we keep the average schooling years unchanged from 2010 to 2012, instead interpolating a decline over 2013‐2018, based on our calculations of average years of schooling for 2015 and 2018 respectively. For the infrastructure index,

> 36 See Milton (2019) for a discussion of how Syria’s higher education system survived quantity wise, despite general expectations that higher education suffers relatively more during conflict, but that quality had been eroded and political control over campuses increased.

> 37 Educational attainment for pre‐conflict Syrians five years and older (2007): 83 percent with primary education and below, 9.5 percent with secondary education and 7.2 percent with tertiary education. Syrian refugees five years and older (2014): 83.6 percent with primary education and below, 11.4 percent with secondary education and 5.1 percent with tertiary education (Jordan); 86.7 percent with primary education and below, 8 percent with secondary education and 5.3 percent with tertiary education (Lebanon).

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