Cumulative causation is Gunnar Myrdal's direct challenge to the equilibrium assumption at the heart of mainstream economics. Where orthodox theory held that market forces tend toward self-correction, Myrdal's empirical work across three continents demonstrated the opposite: initial advantages create further advantages, initial disadvantages create further disadvantages, and the spirals compound rather than converge. The principle operates through multiple reinforcing channels simultaneously — economic, educational, institutional, psychological, cultural — each feeding the others. Applied to AI, the framework predicts that the gains of the transition will concentrate among those who already possess the infrastructure, talent, capital, and institutional capacity to use the tools, while the costs fall on those who do not. The concentration is not accidental; it is structural, and it reverses only through deliberate institutional intervention.
Myrdal developed the principle across thirty years of empirical work, beginning with An American Dilemma in 1944 and culminating in Asian Drama in 1968. In the American South, he documented how racial discrimination in employment reduced Black earnings, which reduced Black investment in education, which reduced Black productivity, which was cited as justification for continued discrimination — a perfect circle in which each disadvantage produced the next. In South and Southeast Asia, he traced how the absence of industrial infrastructure in poor regions drove capital toward already-industrialized regions, further depleting the peripheral regions' capacity to invest. The pattern repeated across contexts because the underlying mechanism is structural: advantage is self-amplifying when the institutions that distribute it are themselves products of the distribution.
The equilibrium assumption Myrdal displaced was never merely academic. It was a policy prescription: if markets self-correct, intervention is unnecessary. The assumption served the interests of those who benefited from existing distributions by providing intellectual cover for inaction. Myrdal's empirical demolition of the assumption carried a direct policy implication: because cumulative causation does not self-correct, deliberate interventionist construction of institutions is required to redirect the flow of advantage toward populations the market systematically bypasses.
The AI transition tests Myrdal's framework under conditions he could not have anticipated: computational speed, global scale, and a technology whose benefits compound with the same self-reinforcing logic his theory describes. The speed of adoption that Segal celebrates also measures the speed of divergence: early adopters accumulate productivity advantages, market positions, and experiential knowledge that later adopters cannot replicate by acquiring the tool at a later date. Within organizations, the Berkeley study documented workers colonizing protected time. Between organizations, the Software Death Cross transferred value from the less-positioned to the already-positioned. Between nations, AI amplifies the gap through the same channels Myrdal identified.
The circularity is not a logical flaw in the analysis; it is the empirical reality the theory describes. The institutions that could break the cycle — educational systems, regulatory frameworks, redistributive mechanisms — are themselves shaped by the distributional patterns they would need to overcome. The schools that most need reform are least equipped for it. The regulatory bodies most capable of restraint are most captured by industry. This is not defeatism. Myrdal understood circularity as the grounds for intervention rather than despair — intervention that acknowledges the circularity and works within it rather than pretending the circle will break on its own.
The principle received its fullest theoretical statement in Myrdal's 1957 Economic Theory and Under-Developed Regions, where he argued that the equilibrium assumption was incompatible with observed patterns of regional development. He refined it across the three volumes of Asian Drama (1968) and defended it in his 1974 Nobel Prize lecture. The concept became foundational to institutional economics, development studies, and the analysis of structural inequality — the analytical machinery that made visible what market-equilibrium frameworks systematically obscured.
Self-reinforcement, not self-correction. Social systems in the normal case produce forces that drive them further in the initial direction, not counterbalancing forces that restore equilibrium.
Multiple channels simultaneously. The compounding operates through economic, educational, institutional, psychological, and cultural mechanisms at once, each reinforcing the others.
The equilibrium assumption as political act. Claiming that markets self-correct is itself a policy prescription — a way of rendering inaction intellectually respectable.
Intervention as logical necessity. Because the circle does not break on its own, deliberate institutional action is the only force that can alter the trajectory.
Circularity as grounds for action. The fact that the institutions needed to break the cycle are themselves products of the cycle does not counsel despair; it specifies the political work required.