A model of the progress of urbanization, based on empirical evidence from Europe. In a traditional society, urbanization is below 20%, and the rate of urbanization is slow, so the curve starts gently. With industrialization, and a rise in the importance of manufacturing and services, the pace of urbanization quickens, but the curve slackens after about 75%. While most developed countries have reached this third stage, the countries of the developing world are still on a rising curve of urbanization, often with a steeper gradient than is characteristic of advanced economies.

Some geographers believe that counter-urbanization constitutes a fourth stage, when urban populations percentages fall; others that counter-urbanization is temporary.

Urbanization curve