> In the nineteenth century, cities grew quickly. Between 1800 and 1914, the population of Berlin’s metropolitan area grew twenty times, Manchester’s twenty-five times, and New York’s a hundred times. Sydney’s population grew around 240 times and Toronto’s maybe 1,700 times. Between 1833 and 1900, Chicago’s population grew around five thousand times, meaning that on average it doubled every five years.

> Raw population growth understates the speed of expansion. The number of people per home fell, and, in Britain and America, the size of the average home roughly doubled. At the same time, those homes fit on a smaller share of land, with huge swaths given over to boulevards, parks and railways. The expansion in surface area was thus often several times greater than the expansion in raw population. Meanwhile, real house prices remained flat, while incomes doubled or tripled, generating a huge improvement in housing affordability. Far more people were enjoying far larger homes for a far smaller share of their income.