Sen opens the book with a deceptively simple proposal that overturns economists’ typical ideas about economic development: He argues that development should be measured by increases in people’s freedom rather than by gross national product (GNP) or other purely economic measures. For example, considering political participation or education as important only if it boosts GNP misconstrues the goal of development. Civil rights and education should be valued in themselves. A simple measure of income per capita in a country also misses the fact that, for example, citizens of China or Sri Lanka have dramatically longer life expectancies than citizens of countries with higher per capita GNPs (like South Africa), as well as longer life expectancies than African Americans within the wealthy United States. So, GNP fails to capture the actual quality of life that these different people experience. Sen argues that freedom should be the evaluative measure of success and that it also is a key instrument for achieving that success.

Since freedoms are interconnected, supporting people’s free agency in any one area helps achieve development in other areas, as well. Sen warns against a simplistic view of market-oriented economies.