Three Centuries of Thinking About Inequality

Smith: Inequality as a Moral Problem

Adam Smith is often claimed by free-market advocates who read only the parts of The Wealth of Nations that suit them. But Smith was deeply concerned with inequality — not merely as an economic phenomenon but as a moral one. In The Theory of Moral Sentiments (1759), he argued that human beings had a natural tendency to admire the rich and despise the poor, and that this tendency was a source of moral corruption.

In The Wealth of Nations (1776), Smith was explicit: “No society can surely be flourishing and happy, of which the far greater part of the members are poor and miserable.” He recognized that the division of labor — the engine of productivity growth — could also degrade workers, reducing them to performing a single repetitive task until they became “as stupid and ignorant as it is possible for a human creature to become.” His proposed remedy was public education, funded by the state.

Smith understood that the power dynamics of the labor market were asymmetric. “Masters are always and everywhere in a sort of tacit, but constant and uniform combination, not to raise the wages of labour above their actual rate,” he wrote. Workers, being more numerous and more desperate, were at a structural disadvantage. Smith did not celebrate this; he observed it.

Ricardo and Marx: The Laws of Distribution

David Ricardo, writing in the early nineteenth century, formalized the question of distribution. His theory of rent showed how landlords captured an increasing share of national income as population grew and less fertile land was cultivated. The interests of landlords, Ricardo argued, were “always opposed to the interests of every other class in the community.” His analysis was the first systematic attempt to show that distribution was not merely a matter of individual fortune but of structural relationships between classes.

Karl Marx took Ricardo’s framework and radicalized it. For Marx, the central fact of capitalism was exploitation: workers produced more value than they received in wages, and the surplus was appropriated by capitalists as profit. Inequality was not a bug in the system; it was the system. The tendency of capitalism, Marx argued, was toward increasing concentration of wealth and the immiseration of the working class — a prediction that appeared to be confirmed by the squalor of mid-Victorian England.

Marx was wrong about immiseration — real wages eventually rose dramatically, particularly after the reforms of the late nineteenth and early twentieth centuries. But his insistence that distribution was determined by power, not merely by productivity, influenced a century of economic thought.

The Neoclassical Interlude

The marginal revolution of the 1870s — associated with Jevons, Menger, and Walras — reframed the question of distribution. In the neoclassical framework, each factor of production (labor, capital, land) was paid its marginal product: the value of the additional output produced by the last unit employed. If workers were paid less, it was because their marginal product was lower. Inequality reflected differences in productivity, which in turn reflected differences in skill, effort, and human capital.

This framework was mathematically elegant and ideologically convenient. It implied that market outcomes were, in a meaningful sense, fair: you got what you contributed. Redistribution was possible but costly, since it distorted incentives and reduced efficiency. The best way to reduce poverty was to grow the pie, not to redistribute it.

Simon Kuznets, in the 1950s, proposed what appeared to be an empirical law: inequality first increased during industrialization, then decreased as economies matured. The “Kuznets curve” — an inverted U — suggested that inequality was a transitional problem that market economies would naturally resolve. For the postwar generation, observing the rise of the middle class in Western democracies, this seemed plausible.

Piketty: The Return of Capital

Thomas Piketty’s Capital in the Twenty-First Century (2014) demolished the Kuznets curve with two centuries of data. The decline in inequality from 1914 to 1980, Piketty showed, was not the natural outcome of economic development. It was the product of two world wars, the Great Depression, progressive taxation, and deliberate policy choices. Remove those exceptional circumstances, and the underlying tendency of capitalism was toward increasing concentration of wealth.

Piketty’s central formula — r > g, meaning the rate of return on capital tends to exceed the rate of economic growth — captured why. When returns on wealth outpace growth, inherited capital accumulates faster than earned income. The rich get richer not because they are more productive but because they already own capital. Over time, this produces a “patrimonial capitalism” in which birth matters more than talent or effort.

The response to Piketty was intense and divided. Critics challenged his data, his assumptions, and his policy prescriptions. But his core achievement was to force the profession to take inequality seriously as an object of study — and to demonstrate that the distribution of income and wealth was not a side-effect of growth but a central feature of how capitalist economies work.

Where We Stand

The economics of inequality in the 2020s is richer and more contentious than at any point since Marx. The evidence is clear that inequality in most advanced economies has increased significantly since 1980. The causes are debated: globalization, technological change, declining unionization, tax policy, financialization, and the changing structure of labor markets all play roles.

What has changed most is the recognition — or re-recognition — that distribution is not merely an economic question. It is a question about power, institutions, and political choices. Smith knew this. Marx knew this. The neoclassical interlude, with its comforting story about marginal products and rising tides, temporarily obscured it. Piketty and others have brought it back into focus. The question now is not whether inequality matters, but what — if anything — democracies will choose to do about it.

Between Classical Political Economy and the Marginalists: Mill, the Distributive Question, and the “Laws of Production”

John Stuart Mill, writing in the middle of the nineteenth century, occupies a useful hinge position. He helped carry forward Ricardian attention to distribution as a set of institutional outcomes while also embracing emerging marginal tools for thinking about exchange in particular markets. Mill’s often-quoted line that the laws of production resemble physical necessity more than the laws of distribution—because distribution is a matter of human arrangement—matters to intellectual history. It keeps alive the Smithian insight that “natural” distributive patterns are rarely natural in a moral sense, even if they feel inertial.

Mill is also a reminder that the history of ideas about inequality is not a straight line from Marx to marginalism. Reformist currents in classical political economy asked whether education, inheritance taxation, and cooperative experiments could reshape the social meaning of private property without assuming central planners had perfect information. This milieu is part of the story behind later experiments with progressive taxes, land value ideas, and the slow construction of the welfare state—none of which were foregone conclusions when the classical economists wrote.

From Factory Acts to the Postwar Compromise: Policy as Distribution in Drag

A reader who only moves from Marx to the marginal product cannot explain why mid-twentieth century inequality in several rich countries compressed for decades. Wartime mobilization destroyed capital and shifted political coalitions. Unions codified rent-sharing in key industries. Progressive taxation and estate taxes made extreme wealth costlier to perpetuate at the top. Financial repression and restrictions on cross-border capital mobility—often undersold in glib “Great Compression” tellings—changed who could earn and reinvest at scale in which jurisdictions. None of that is a pure technology story; it is a policy and geopolitics story, even when productivity growth also mattered.

Piketty’s work can be read, in this light, as an invitation to reintegrate those policy and shock variables into a long distributive narrative without pretending they were automatic Kuznets inevitabilities. The question is not only whether the rate of return on capital tends to exceed the growth rate, but which institutional filters once held the two in a different relationship for broad swaths of the wealth distribution than we see in many countries today.

Gender, Unpaid Work, and What “Inequality” Misses in Headline Statistics

A discussion worth extending—because it reappears whenever economists argue about the top one percent and the bottom fifty—is that labor-market earnings alone understate the full political economy of who does what in a society. Feminist economics and historical work on household production remind readers that unpaid care and domestic labor shape who can participate in waged markets on what terms, and how “free” labor contracting is when alternatives are constrained by family structure, childcare access, or migration regimes.

Smith’s worry about the moral and cognitive costs of extreme specialization pairs awkwardly but fruitfully with modern time-use evidence showing how unpaid work still falls unevenly by gender in many high-income economies. None of that replaces Piketty’s top-wealth-shares message; it complements it by showing how inequality, as a lived experience, can run through hours, autonomy, and care burdens as much as through bank accounts alone.

Globalization, Tax Competition, and the Reopening of the Top Tail

Since the 1980s, a commonly cited set of forces has pushed on the upper tail of income and wealth distributions in multiple countries: offshoring and global value chains; skill-biased technical change; decline in private-sector union coverage; deregulation of some parts of finance; and tax reforms that lower top marginal rates or reshape capital income taxation in ways that interact with cross-border arbitrage and entity choice.

No single factor explains every country’s trajectory, because institutions differ. Nordic countries retained strong tax-and-transfer systems and still face top-end pressures in some dimensions. The United States saw a particularly sharp concentration at the very top in certain measures of labor and capital income, especially when combined with a complex system of executive compensation and equity grants that can separate a tiny group from the rest of the upper-middle class. Readers who want a bridge to open-economy politics can ask how international treaties on property rights, investor protections, and royalty flows affect where profits are booked and who can capture the returns to intangible capital—questions that make inequality less about a domestic Gini alone and more about jurisdiction and power.

The Measurement Maze: Pre-Tax, Post-Tax, Wealth, and Capitalized Flows

Intellectual progress in inequality research is tied to data craft. Piketty and collaborators pushed on historical income-tax microfiles and estate data; other teams emphasize post-tax income including transfers for welfare comparisons; wealth scholars warn that capital income is not the same thing as the stock of wealth, especially when valuations are volatile; synthetic control and distributional national accounts attempt to reconcile what household surveys undercount at the top with what macro totals imply.

A non-specialist can still profitably ask, of any chart: is this pre-tax or post-tax? Is it individuals or tax units? Does it include imputed rent? Are pensions valued at face or at market? The three-century arc of this article is not that every metric agrees; it is that careful definition work matters as much as moral outrage when we debate what to do.

Heterodox Traditions, Power, and the Return of Distributive Politics to Core Macro

Post-Keynesian, institutionalist, and Marxian research programs never fully accepted that distribution could be treated as a residual appendix to growth theory. Their arguments about markups, finance, and class bargaining sometimes overlap with mainstream labor and public finance now that top inequality and housing wealth have returned to center stage in political rhetoric. In that sense, Piketty is less a rupture and more a synthesis vehicle: a way for large audiences to re-encounter questions Smith and Marx posed, with new databases and clarity about the exceptional mid-century compression episode that once made a simple Kuznets story look like destiny.

Looking Forward: Climate, Demography, and the Distributive Stakes of Transitions

The 2020s add new wrinkles to old debates about inequality and policy. Aging societies face pension arithmetic that interacts with who owns housing and who rents. The green transition raises questions about who pays up front for durables and infrastructure and who captures long-horizon subsidies. Pandemic shocks showed how quickly labor-market inequalities can widen or narrow along lines of frontline work, remote work, and savings for those who could accumulate during dislocation.

If there is a unifying moral to three centuries of writing on this topic, it may be modest: the distribution of well-being is not a single number. It is a set of outcomes produced by technology, institutions, shocks, and contested political choice. Smith’s flourishing criterion and Marx’s class analysis still serve as opposing guardrails for anyone tempted either to moralize poverty as purely personal failure or to read every market outcome as a fair scoreboard of contribution.

Further Reckonomics Links

Readers who want to go deeper into related threads on this site might pair this historical tour with entries on classical wages and the reserve army of labor, contemporary rentier capitalism, Kaldorian and Kaleckian distributive macro, and the global transformations discussed in imperialism and open-economy inequality primers—not because one article can replace them, but because the map of ideas is necessarily wider than any single narrative of the last three hundred years can capture in a short commentary piece without a bibliography the size of a monograph.