Traditional societies depend on subsistence agriculture and barter trade, producing just enough for families to survive. As agriculture becomes more commercial and investments in transport and industry start, urbanization and specialization begin, marking the pre-conditions for take-off. The take-off stage sees a rapid rise in investment and massive growth in manufacturing, accompanied by social, political, and institutional changes to stimulate city growth. Most developed countries have reached the age of high mass consumption, where manufacturing and services dominate the economy, wages and standards of living are high, and demand for resources is also high.