A thesis developed by the economist Thomas Malthus (1766–1834), stating that per capita incomes would be driven down to subsistence level by a tendency for population to grow faster than output. The argument was that while the population grows exponentially the supply of resources, such as food and shelter, can only grow linearly, which puts a limit on the size of population a given area can support. This, in essence, is the problem of the growth and distribution of resources.