Sanchez de la Sierra (2017) gathers panel data on armed actors in 650 locations of Eastern Congo to explain the
emergence and trajectories of Tilly (1985)’s essential functions of the state. A demand shock
for coltan, a bulky commodity, leads violent actors to organize monopolies of violence, tax
output, and provide protection at coltan-producing locations. A similar shock for gold, which
can be concealed to avoid taxes, does not. Instead, it leads armed actors to form monopolies
of violence in the villages in which gold miners spend their income, and to introduce consumption
and wealth taxes, as well as fiscal and legal administrations to reduce evasion. This
process benefits the population, only if such functions are embodied by a popular militia.