Paul Samuelson
Citation: For the scientific work through which he developed static and dynamic economic theory.
The key idea
Economic theory has the structure of physics: optimisation under constraints, with comparative statics and dynamic stability following from the same maximisation principles.
The explanation
Samuelson's Foundations of Economic Analysis (1947) rebuilt economic theory on calculus and Lagrangians. Consumer choice, producer behaviour, public finance, trade, capital theory — each became a constrained optimisation. He proved the revealed-preference theorem (you can infer preferences from choices) and the factor-price-equalisation result in trade.
Why Africa should care
Every cost-benefit calculation a Kenyan ministry runs (shadow prices in road appraisals, opportunity-cost arguments in budget hearings) uses Samuelson's framework. The lifecycle model of consumption underpins Kenyan pension reform design and the Hustler Fund debates about credit-vs-savings.
How to use it
When evaluating a project, write the Lagrangian: what is being maximised, subject to which constraints, with what shadow prices? Most policy disagreements reveal themselves to be disagreements about one of these three.
Canonical works
- Paul A. Samuelson (1947) "Foundations of Economic Analysis" Harvard University Press
- Paul A. Samuelson (1948) "Economics" McGraw-Hill
More from Foundations · 1969-1979
- 1969Ragnar Frisch and Jan Tinbergen
Economics is a measurable science. Build dynamic equations of the economy, estimate them with data, use them to forecast and design policy.
- 1971Simon Kuznets
Growth is structural transformation, not a single line on a chart. Inequality follows an inverted U as economies industrialise — the Kuznets curve.
- 1972Kenneth Arrow and John Hicks
When can the totality of competitive markets simultaneously clear, and when is that outcome socially efficient? Arrow-Debreu (1954) proved existence; the First Welfare Theorem proved efficiency — under restrictive assumptions.
- 1973Wassily Leontief
An economy is a matrix. Each sector produces output by buying inputs from other sectors. Once you know the matrix of inter-industry flows, you can compute the total impact of any final-demand change.
- 1974Gunnar Myrdal and Friedrich Hayek
Two utterly opposite visions: Myrdal — economies are bound up with social institutions and demand activist policy; Hayek — markets coordinate dispersed knowledge in ways no planner can replicate.