household head’s sector of employment. Panel a and c show the backcasted poverty rates at the US$1.90 and US$3.20 poverty lines, panel b and d show the backcasted series of number of people living below these two lines. Population estimates are from the WDI. Different values of the pass-through rate are calculated using household survey data from PovcalNet and National Accounts data from the WDI.

We also test the robustness of the results to relaxing the assumption that growth in the national accounts is passed through to growth in household consumption at the same rate across the entire consumption distribution.<sup>23</sup> To do this, we construct three separate “growth incidence curves” (GICs) using imputed consumption data from the survey-to-survey imputation exercise: the time periods considered are 2010/11 to 2018/19, 2010/11 to 2015/16, and 2015/16 to 2018/19 (see Table 12 in the Appendix for these GICs). Over the entire 2010/11 to 2018/19 period, Nigeria’s GIC was sloped _slightly_ downwards, implying that poorer Nigerians benefited slightly more from growth than richer Nigerians: this corresponds to a small drop in the Gini coefficient of just 0.6 points over this period.<sup>24</sup> However, this picture is somewhat distorted by the effects of the 2016 oil recession. The GICs based on imputed data indicate that richer households lost out significantly more than poorer households when the economic shock hit.<sup>25</sup> However, during the first part of the decade – when Nigeria was growing more strongly – richer Nigerians disproportionately enjoyed the gains. Put differently, the consumption of richer Nigerians was more sensitive to Nigeria’s overall growth performance than the consumption of poorer Nigerians. Thus, it is important to separate out the periods before and after the 2016 recession when constructing the GICs and testing the robustness of the backcasts. Once they have been constructed, the GICs are then used to adjust the pass-through rate applied to each decile of the consumption distribution, holding the overall _average_ pass-through fixed at 1.<sup>26</sup> Relaxing the assumption of distribution-neutral pass-through alters the backcasted trend, but even under the assumption that more growth was passed through to poorer Nigerians during the decade to 2018/19, poverty reduction over that period remains in single digits. Figure 5 shows that using the 2010/11-2018/19 GIC – which was slightly pro-poor – in the backcasting exercise results in a larger reduction in poverty over the decade, such that the estimated poverty headcount rate is 47.9 percent in 2009 (1.6 percentage points higher than our main backcasted result). Conversely, using the 2015/16-2018/19 GIC results in a more

> 23 In 2018/19, _overall_ inequality in Nigeria was moderate: the Gini coefficient was 35.1. However, spatial inequality – especially along the north-south divide – was far more pronounced (Lain and Vishwanath, 2021; Blumenstock et al., 2021).

> 24 Data on spatial inequality of non-monetary indicators also suggest that inequality did not significantly drop in the decade prior to the COVID-19 crisis. According to the DHS, the north-south gap in terms of education and basic infrastructure did not close substantially over this period (Lain and Vishwanath, 2021).

> 25 Labor market indicators from the same period show similar patterns (see Jenq, Lain, and Vishwanath (2021)).

> 26 This means that the average growth in consumption is the same as in the main results in Figure 1.

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