From the early 1950s Bangkok's population grew at a strikingly faster rate
than the country and other growing urban centres in Thailand (London
1980: 32-5). The key factors reinforcing Bangkok's primacy were both
demographic and economic in character. Differentials between farm
incomes and urban wage rates had been minimal prior to the Second World
War, largely due to the availability of rural land, demand for agricultural
labour in the highly productive central region and a relatively low popu-
lation growth rate. These conditions changed in the post-war period. An
accelerating population growth (from 1.9 per cent per annum 1937 to 3.2
per cent per annum 1947-60) put pressure on rural farm incomes, leading
to increasing tenancy, indebtedness and reduction in farmholding sizes.
Significant disparities emerged between wage rates for unskilled labour in
the burgeoning urban economy and the countryside. Bangkok benefited
disproportionately from Thailand's post-war economic growth.