For those unable or unwilling to find employment, there is Basic Assistance, the United Nations’ global welfare program. Over half of the Earth’s populace relies on it for survival. Without jobs, these people have no money, so Basic provides shared accommodations in government housing complexes, meagre food in the form of Gray-tasting textured protein and enriched rice, minimal medical care in government clinics, and even recycled paper clothing, dispensed from automated kiosks with a thumbprint. All of these services are provided free of charge, but those on Basic are subject to mandatory contraception and cannot legally have children, apart from the regular “baby lottery” allowing for a small number of births each year

From the Expanse wiki.

Earth has a population of over 30 Billion with a B when the series starts.