2000-2014 (Elvidge et al. 2014). For the period 2012-2020, we use the average nightlights using Black Marble data from NASA.<sup>11</sup> However, the results show that none of the estimates for the road variables used in the previous specifications are significant (Table A9) but such results should be cautiously interpreted. The use of nighttime lights for rural parts of DRC might be problematic because of the limited satellite coverage for most parts of DRC and the limited insights brought by nighttime lights for rural areas. However, nighttime lights remain the only available data for such geographic coverage and time frequency. The results do not support the assumption that new road projects may reduce violence through a significant increase in economic activities. Given that the estimates vary across periods, we check whether our results on violence reductions with road building are driven by specific periods and find no evidence for this (Table A10). From the previous regressions, we find that the completion of roads when gold mining revenue increases is associated with more violence against civilians and battles. This can be explained by an amplification of rapacity effects.<sup>12</sup> We also know that the opposite is true with roads in areas with high cobalt revenue and in rugged areas, where their violence-reducing effect is amplified. These effects would be aligned with both an opportunity cost channel and a state capacity channel as reported by World Bank practitioners.

The last channel of interest is the adaptation of armed groups from being “roving bandits”, exerting violence to extract maximum benefit in the short term, to “stationary bandits” that set up regular taxation systems and leave a portion of resources for the population to use for accumulation, investment, and subsequent increases in production. Improved roads could reduce violence against civilians and generate taxable traffic that can generate longer-term revenue, through roadblocks for example, rather than through more violent, ‘roving bandit’ tactics. More work and access to more granular data will be needed to fully disentangle these effects.

Overall, our results suggest that roads do not affect violence only through one channel but might increase violence through increasing opportunities for attacks and raids while at the same time increasing stability by increasing state capacity or opportunity costs for violence. Such a complex role of trade linkages is consistent with recent theoretical work (Couttenier et al. (2023)).

# **6 Conclusion**

Understanding the impacts of roads on violence is important to better support the efforts of stabilization and reconstruction in conflict-ridden countries. The present paper quantifies the impact of road construction and rehabilitation on violence in the DRC by using temporal variation in road project rehabilitation using a new database of large inter-city road projects

> 11 We use the R package for extraction of the yearly data from `https://github.com/worldbank/black marbler?tab=readme-ov-file#bearer-token-` .

> 12This goes against the findings from McGuirk and Burke (2020) about producing cells where higher crop prices lead to a lower probability of conflict in food-producing areas.

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