2012; Jones et al., 2014). The approach adopted by Uwezo has been inspired by exercises carried out in India by the Assessment Survey Evaluation Research Centre (ASER), which has surveyed the literacy and numeracy abilities of over 500,000 children each year since 2005. As with ASER, the target population of the Uwezo surveys has been children (residing in households) aged between the official starting-school age and 16. The surveys have been designed to be representative at both national and district levels, based on the administrative 13 classifications in the most recently available population census. Excluding the initial surveys, five rounds of the Uwezo surveys have been completed (2011-2015) and are used here.

In each assessment, the surveys collected information at the household level covering household characteristics and the demographic and educational details of all resident children (e.g., age, gender, whether or not attending school, etc.). Within each household, the children of school age were individually administered a set of basic oral literacy and numeracy tests. These tests have been based on a common template, but have been tailored to each country and varied by survey round. Specifically, in each round and country, local experts have taken the template and developed item content to reflects competencies stipulated in the national curriculum at the grade 2 level. That is, the tests are anchored to skills that should be achieved by the majority of pupils after two years of completed schooling.

The literacy and numeracy tests (the Uwezo tests) are described in detail in Jones et al. (2014). The literacy tests refer to national languages of instruction in which pupils are tested at the end of primary school – i.e., English and Kiswahili in Tanzania and Kenya; and just English in Uganda. Importantly, the Uwezo tests are not adapted to the children’s ages or their completed level of schooling. Given that they focus on basic competencies, it is thus unsurprising there are strong age- related differences, which affect both the level and variance of scores _between_ age cohorts. From the present perspective, this between-cohort variation can be considered unwanted noise (see Mazumder, 2008).<sup>14</sup> As a result, so as to construct an overall metric of achievement, we transform raw integer scores on the individual tests in three steps. First, each score is standardized by age, such that the individual test scores have means of zero and standard deviations of 100 for each age group. Second, we calculate weighted means of the age-standardized scores on each test, placing equal weight on the literacy and numeracy components. This gives a synthetic or overall test score, the primary outcome of interest hereafter. Third, to facilitate interpretation and to address potential differences in the test difficulty between countries and rounds, we normalize this measure for each country and

> 13 In some survey rounds, however, administrative difficulties meant that certain districts could not be surveyed. Throughout, (adjusted) survey weights are used that take into account these implementation issues.

> 14 We recognize the contribution of different variance components may vary across age cohorts and we investigate this in our empirical analysis.

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