In Kenya’s capital Nairobi, business as usual has begun to return to the central commercial district, as pedestrians throng crowded streets where hawkers sell their wares—at least until a government mandated curfew forces everyone to rush home by 7 pm.To get around, most commuters rely on fleets of privately owned minivans and buses, called matatus, an example of the kinds of informal transportation services common in the developing world. Like businesses everywhere, they have been hard hit by the Covid-19 pandemic.Stay-at-home orders and the dusk-to-dawn curfew have reduced ridership. The…