Amartya Sen's Poverty and Famines (Oxford, 1981) made a single radical claim: famines are not caused by absolute food shortages. The 1943 Bengal famine, in which roughly three million people died under British colonial rule, occurred in a year when Bengal's per-capita food availability was within normal range; the 1974 Bangladesh and 1972-74 Ethiopian famines showed the same pattern. What failed was entitlement — people's capacity to acquire food through wages, trade, or transfers. Sen's argument was that food availability does not feed people; the ability to command food, through whatever institutional channels exist, does. A famine is therefore a failure of social and political organization, not of agriculture. The book founded the capabilities approach — development as the expansion of substantive freedoms — and reframed how the World Bank, the UNDP, and most national development agencies think about poverty.
Two questions organize the field. Why are some countries rich and others poor — and what, concretely, makes people's lives better? Three frameworks compete on the first. Robert Solow's 1956 growth model treated output as a function of capital, labor, and a residual called total factor productivity, and predicted conditional convergence: poor countries should catch up because capital returns more where capital is scarce. East Asia confirmed it; most of Africa and Latin America did not. Paul Romer's endogenous-growth theory replaced Solow's unexplained TFP with ideas as a non-rival input — once a useful idea exists, anyone can use it, making increasing returns possible and putting R&D and education at the centre of growth. Daron Acemoglu and James Robinson pushed deeper in Why Nations Fail and the work that won the 2024 Nobel: capital and ideas circulate, but do little where institutions extract upward instead of rewarding broad participation. Their colonial settler-mortality natural experiment is one of the most-cited findings in empirical economics.
The second question drove a methodological revolution. Esther Duflo, Abhijit Banerjee, and Michael Kremer founded J-PAL at MIT in 2003 and brought the randomized controlled trial from medicine into development. Deworming programmes, conditional cash transfers, bed-net pricing, and microfinance impact were tested in field experiments rather than argued from theory; the trio shared the 2019 Nobel. The field's centre of gravity moved from grand causal theory — Jeffrey Sachs's big-push case for coordinated aid versus William Easterly's warning that aid distorts the institutions it claims to help is the canonical pair — toward identified, narrow, replicable evidence. The industrial-policy revival, anchored on the East Asian record and championed by Ha-Joon Chang and Mariana Mazzucato, runs counter to both schools and is the live argument of the 2020s.
China's poverty reduction between 1980 and 2020 — roughly 800 million people lifted out of extreme poverty — is the single largest development achievement in human history. Whether India can replicate the labor-intensive manufacturing path in an age of automation and climate constraints is the central open question of the decade. Africa's growth has split sharply by country in a way the institutions argument predicts: Rwanda, Ethiopia, and Ghana have sustained 5%+ growth for two decades while Nigeria, South Africa, and Egypt have stagnated. Climate adaptation has emerged as the field's defining problem — adaptation-finance needs run to several hundred billion dollars annually by 2030 against current flows an order of magnitude smaller, and how that gap closes will determine whether the institutions-and-investment template still works in a world the template did not anticipate.