Table 9: The effects of minerals’ value on lights Gini index Dependent variable: district lights Gini index

|||Constant m|ineral prices|||Average m|ineral prices||
|---|---|---|---|---|---|---|---|---|
||Model 1|S.E.|Model 2|S.E.|Model 3|S.E.|Model 4|S.E.|
|SITC_1 x Low value x log(Price)|0.131<sup>***</sup>|[0.001]|0.126<sup>***</sup>|[0.006]|0.149<sup>***</sup>|[0.001]|0.137<sup>***</sup>|[0.014]|
|SITC_2 x Low value x log(Price)|0.137<sup>***</sup>|[0.007]|0.138<sup>***</sup>|[0.008]|0.195<sup>***</sup>|[0.008]|0.198<sup>***</sup>|[0.011]|
|SITC_3 x Low value x log(Price)|0.013|[0.089]|0.014|[0.089]|0.022|[0.085]|0.023|[0.085]|
|SITC_5 x High value x log(Price)|-0.006|[0.049]|-0.005|[0.049]|-0.007|[0.062]|-0.006|[0.062]|
|SITC_6 x Low value x log(Price)|-0.086|[0.080]|-0.085|[0.078]|0.026|[0.062]|0.025|[0.062]|
|SITC_7 x Low value x log(Price)|-0.045<sup>***</sup>|[0.010]|-0.045<sup>***</sup>|[0.010]|-0.037<sup>***</sup>|[0.008]|-0.037<sup>***</sup>|[0.008]|
|SITC_9 x Low value x log(Price)|-0.003|[0.020]|-0.003|[0.019]|-0.002|[0.019]|-0.002|[0.019]|
|SITC_10 x Low value x log(Price)|-0.047|[0.057]|-0.048|[0.056]|-0.039|[0.045]|-0.039|[0.044]|
|SITC_11 x Low value x log(Price)|-0.051|[0.031]|-0.051|[0.032]|-0.046|[0.028]|-0.046|[0.029]|
|SITC_12 x Low value x log(Price)|0.013|[0.009]|0.013|[0.009]|0.014|[0.009]|0.014|[0.009]|
|SITC_13 x Low value x log(Price)|0.017|[0.143]|0.016|[0.143]|0.750<sup>*</sup>|[0.416]|0.747<sup>*</sup>|[0.419]|
|SITC_14 x High value x log(Price)|0.005|[0.019]|0.005|[0.018]|0.033|[0.032]|0.033|[0.031]|
|SITC_15 x Low value x log(Price)|-0.155<sup>***</sup>|[0.003]|-0.155<sup>***</sup>|[0.003]|-0.139<sup>***</sup>|[0.003]|-0.139<sup>***</sup>|[0.003]|
|SITC_16 x Low value x log(Price)|-0.110|[0.106]|-0.111|[0.104]|-0.098|[0.092]|-0.099|[0.091]|
|SITC_17 x Low value x log(Price)|0.001|[0.027]|0.001|[0.027]|0.004|[0.025]|0.004|[0.026]|
|SITC_18 x High value x log(Price)|0.040<sup>**</sup>|[0.018]|0.040<sup>**</sup>|[0.018]|0.034<sup>**</sup>|[0.016]|0.035<sup>**</sup>|[0.016]|
|Fixed effects|Yes||Yes||Yes||Yes||
|Controls|No||Yes||No||Yes||
|N|19298||19298||19298||19298||
|R-squared|0.763||0.763||0.763||0.763||
|Countries|38||38||38||38||

Notes: (1) The table shows the regression results for a sample of 2,182 districts in 653 regions across 38 countries in Africa during 2001–2012. (2) The regressions use the classification of minerals’ value to explain spatial-temporal variations in inequality. (3) Gini index is at the district level and measured using night-time light intensity. (4) The standard errors, clustered at the country level, are in the brackets. (5) Constant (measured at constant 1998 US dollars) and average (measured as annual averages) prices come from USGS. (6) High value refers to mining sites where high-value minerals are extracted, whereas low value refers to places where low-value minerals are extracted. (7) Fixed effects include time fixed effects, district fixed effects, regional fixed effects, country fixed effects, and country-year fixed effects. (8) Controls include a proxy for agricultural productivity, rainfall, population sizes, lights pixels lit, and district geographical locations (measured in absolute latitudes). (9) SITC_1: helium. (10) SITC_2: garnet (industrial). (11) SITC_3: stones (crushed, dimension), limestone, gypsum, marble, and silicon. (12) SITC_5: diamond. (13) SITC_6: barite, bentonite, clay, dolomite, fluorspar, graphite, salt, vermiculite, fluorine, and graphite. (14) SITC_7: iron ore. (15) SITC_9: cobalt, chromium, niobium (columbium), tantalum, titanium, zirconium, and tungsten. (16) SITC_10: arsenic trioxide, lithium, manganese, pyrophyllite, soda ash, sodium silicate, and wollastonite. (17) SITC_11: phosphate rock and phosphoric acid. (18) SITC_12: cement. (19) SITC_13: diatomite. (20) SITC_14: platinum. (21) SITC_15: nickel. (22) SITC_16: zinc. (23) SITC_17: tin. (24) SITC_18: gold.<sup>*</sup> p < 0.10.<sup>**</sup> p < 0.05.<sup>***</sup> p < 0.01.

Source: authors’ estimations.

Table 10: The effects of the scale of mining activities on lights Gini index Dependent variable: district light Gini index

||Model 1|Constant m<br>S.E.|ineral prices<br>Model 2|S.E.|Model 3|Average m<br>S.E.|ineral prices<br>Model 4|<br>S.E.|
|---|---|---|---|---|---|---|---|---|
|SITC_1 x Large scale x log(Price)|0.132<sup>***</sup>|[0.001]|0.126<sup>***</sup>|[0.006]|0.150<sup>***</sup>|[0.001]|0.137<sup>***</sup>|[0.014]|
|<br>SITC_2 x Large scale x log(Price)|0.133<sup>***</sup>|<br>[0.005]|0.134<sup>***</sup>|<br>[0.007]|0.189<sup>***</sup>|<br>[0.007]|0.193<sup>***</sup>|<br>[0.010]|
|SITC_3 x Large scale x log(Price)|0.011|[0.089]|0.012|[0.089]|0.020|[0.086]|0.021|[0.085]|

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