A surpassingly short, simple characterization of economic underdevelopment by an authority on the subject (and a Kennedy adviser) who maintains that assistance from the affluent fraction of the world to the much slower-growing poor nations is necessary for reasons of prudence, ethics, and ultimate profit. The ""latecomers'"" inability to grow in the manner of their predecessors is explained in terms of five ""basic contradictions"": disproportions between production of food and of people, urban growth and employment, technology and labor supply, savings and consumption, needs and opportunities to trade. She looks toward a world economy applying demand management, wage hikes and progressive taxation on an international scale. Meanwhile, she recommends tariff reform, compensatory finance, common markets and commodity agreements to lessen the inequality. The evident difficulties with all of these point up the oversimplifications of the diagnosis, even apart from the political issues she ignores, and the question of international exploitation she suppresses. But the attempt at historical perspective is preferable to the timeless Rostow ""takeoff"" model. and if chewed, not swallowed, it has considerable pedagogical value.