This book offers a comparative history of inequalities among social classes in human societies. Or rather, it offers a history of equality, because, as we shall see, there has been a long-term movement over the course of history toward more social, economic, and political equality.
This is not, of course, a peaceful history, and still less a linear one. Revolts and revolutions, social struggles and crises of all kinds play a central role in the history of equality reviewed here. This history is also punctuated by multiple phases of regression and identitarian introversion.
Nonetheless, at least since the end of the eighteenth century there has been a historical movement toward equality. The world of the early 2020s, no matter how unjust it may seem, is more egalitarian than that of 1950 or that of 1900, which were themselves in many respects more egalitarian than those of 1850 or 1780. The precise developments vary depending on the period, and on whether we are studying inequalities between social classes defined by legal status, ownership of the means of production, income, education, national or ethno-racial origin—all dimensions that will interest us here. But over the long term, no matter which criterion we employ, we arrive at the same conclusion. Between 1780 and 2020, we see developments tending toward greater equality of status, property, income, genders, and races within most regions and societies on the planet, and to a certain extent when we compare these societies on the global scale. If we adopt a global, multidimensional perspective on inequalities, we can see that, in several respects, this advance toward equality has also continued during the period from 1980 to 2020, which is more complex and mixed than is often thought.
Since the end of the eighteenth century, there has been a real, long-term tendency toward equality, but it is nonetheless limited in scope. We shall see that different inequalities have persisted at considerable and unjustified levels on all these dimensions—status, property, power, income, gender, origin, and so on—and, moreover, that individuals often face inequalities in combination. To assert that there is a tendency toward equality is not to brag about success. Instead, it is to call for continuing the fight on a solid, historical basis. By examining how movement toward equality has actually been produced, we can learn precious lessons for our future and better understand the struggles and mobilizations that have made this movement possible, as well as the institutional structures and legal, social, fiscal, educational, and electoral systems that have allowed equality to become a lasting reality. Unfortunately, this process of collective learning about equitable institutions is often weakened by historical amnesia, intellectual nationalism, and the compartmentalization of knowledge. In order to continue the advance toward equality, we must return to the lessons of history and transcend national and disciplinary borders. The present work—which belongs to the domains of history and the social sciences, and is both optimistic and progressive—seeks to move in that direction.
It is possible to write this Brief History of Equality today chiefly because of the many international studies that have profoundly renewed research in economic and social history in recent decades.
In particular, I shall base my remarks on the multiple works that have provided us with a genuinely global perspective on the history of capitalism and of the Industrial Revolution. I am thinking, for example, about Ken Pomeranz’s study, published in 2000, on the “great divergence” between Europe and China in the eighteenth and nineteenth centuries,1 probably the most important and influential book on the history of the world-economy (économie-monde) since the publication of Fernand Braudel’s Civilisation matérielle, économie et capitalisme in 1979 and the works of Immanuel Wallerstein on “world-systems analysis.”2 For Pomeranz, the development of Western industrial capitalism is closely linked to systems of the international division of labor, the frenetic exploitation of natural resources, and the European powers’ military and colonial domination over the rest of the planet. Subsequent studies have largely confirmed that conclusion, whether through the research of Prasannan Parthasarathi or that of Sven Beckert and the recent movement around the “new history of capitalism.”3
More generally, historians of colonial empires and slavery, along with those who study global, connected history, have made immense strides over the past twenty to thirty years, and I shall lean very heavily on their works. I am thinking in particular of the research of Frederick Cooper, Catherine Hall, Or Rosenboim, Emmanuelle Saada, Pierre Singaravelou, Alessandro Stanziani, Sanjay Subrahmanyam, and many others who will appear as the argument advances.4 My work is also inspired by the renewal of research on people’s history and the history of popular struggles.5
In addition, this brief history could not have been written without the progress made in understanding the historical distribution of wealth among social classes. This domain of research itself has a long history. All societies have produced knowledge and analyses of real, supposed, or desirable differences in wealth between the poor and the rich, at least since The Republic and The Laws (in which Plato recommends that these differences not exceed a ratio of one to four). In the eighteenth century, Jean-Jacques Rousseau explained that the invention of private property and its immoderate accumulation are the origin of inequality and discord among people. However, not until the arrival of the Industrial Revolution did genuine inquiries into workers’ salaries and living conditions develop, along with new sources dealing with income, profits, and properties. In the nineteenth century, Karl Marx tried to make best use of the British financial and inheritance data of his time, even if the means and the material at his disposal were limited.6
In the course of the twentieth century, research on these questions took a more systematic turn. Researchers began to collect on a large scale data regarding prices and salaries, land income and profits, inheritances and plots of land. In 1933, Ernest Labrousse published his Esquisse du mouvement des prix et des revenus en France au XVIIIe siècle (Sketch of the movement of prices and income in France during the eighteenth century), a monumental study in which he shows how in the course of the decades preceding the French Revolution, agricultural wages fell behind relative to the price of wheat and to land income, all in the context of strong demographic pressure. Without claiming it was the sole cause of the Revolution, it seems clear that this development could only increase the growing unpopularity of the aristocracy and of the established political regime.7 In 1965, on the first page of their study Le Mouvement du profit en France au XIXe siècle (The movement of profit in France in the nineteenth century), Jean Bouvier and his coauthors described the research program with which they identified: “So long as the incomes of contemporary social classes remain beyond the scope of scientific inquiry, it will be pointless to try to write a valid economic and social history.”8
Often associated with the Annales school, which was particularly influential in French historical research between 1930 and 1980, this new economic and social history did not neglect the study of property systems. In 1931, Marc Bloch published his classic study on the typology of medieval and modern agrarian systems.9 In 1973, Adeline Daumard presented the results of a vast investigation carried out in nineteenth-century French inheritance archives.10 Since the 1980s, the movement has slowed a bit, but it has left a lasting mark on the practices of research in the social sciences. In the course of the twentieth century, numerous historical studies on wages and prices, income and wealth, and tithes and properties have been published by a multitude of historians, sociologists, and economists, from François Simiand to Christian Baudelot and from Emmanuel Le Roy Ladurie to Gilles Postel-Vinay.11
In parallel, US and British historians and economists also paved the way for a history of the distribution of wealth. In 1953, Simon Kuznets combined the first national accounts, which he had helped establish following the trauma of the Depression, with data from the federal income tax (created in 1913, after a long political and constitutional battle) in order to estimate the share of high incomes in national income.12 The study concerned only a single country (the United States) and a relatively short period (1913–1948), but it was the first study of this kind, and it caused a great stir. Robert Lampman did the same in 1962 with data from the federal tax on inheritance.13 In 1978, Tony Atkinson pushed the analysis further, using British sources on inheritance.14 Alice Hanson Jones went even further back in time, publishing in 1977 the results of a vast inquiry into the property inventories of Americans in the colonial period.15
Drawing on all the earlier studies, a new program of historical research on income and wealth was established in the early 2000s, a program in which I had the good fortune to participate with the decisive support of numerous colleagues, including Facundo Alvaredo, Tony Atkinson, Lucas Chancel, Emmanuel Saez, and Gabriel Zucman.16 In comparison to earlier works, this new wave had the advantage of advanced technical means. Between 1930 to 1980, Labrousse, Daumard, and Kuznets carried out their research almost exclusively by hand, on file cards. Every collection of data and every table of results required a substantial technical investment, sometimes leaving the researcher with little energy for the work of historical interpretation, mobilization of other resources, and critical analysis of the categories, an obligation that no doubt helped weaken a history sometimes seen as too narrowly “serial” (that is, too centered on the production of historical series comparable in time and space, an exercise that may be seen as necessary, but not in any way sufficient, for making progress in the social sciences). In addition, the sources collected during this first wave of studies left few traces, which limited the possible reutilizations and the establishment of a genuine cumulative process.
Conversely, the progress of computerization since 2000 has made it possible to extend the analysis to longer periods and to a greater number of countries. Proceeding from this research program, in 2021 the World Inequality Database (WID.world) brought together the combined efforts of almost a hundred researchers concerning eighty countries on every continent, with data on the distribution of income and wealth going back, in some cases, to the eighteenth and nineteenth centuries, and going forward as far as the first decades of the twenty-first century.17 This broader temporal and comparative perspective has made it possible to multiply comparisons and achieve important advances in the social, economic, and political interpretation of the developments observed. This collective work led me to publish in 2013 and 2019 two studies proposing the first interpretive syntheses on the historical evolution of the distribution of wealth, studies that have helped inform public debates on these questions.18 New research conducted with Amory Gethin and Clara Martínez-Toledano has recently set out to study the transformations of the structure of social inequalities and political cleavages, in line with the studies launched in the 1960s by the political scientists Seymour Lipset and Stein Rokkan.19 While these various research programs have made certain advances possible, we must nevertheless emphasize that much remains to be done to combine diverse methodologies, sources, and research skills to provide a satisfactory analysis of the representations and institutions, the mobilizations and struggles, the strategies and actors involved in the transformations brought to light.
A Brief History of Equality has also been made possible by a new generation of researchers, and interdisciplinary studies that have renewed reflection on the sociohistorical dynamics of equality and inequality at the frontier of history, economics, sociology, law, anthropology, and political science. I refer to the research of Nicolas Barreyre, Erik Bengtsson, Asma Benhenda, Marlène Benquet, Céline Bessière, Tithi Bhattacharya, Rafe Blaufarb, Julia Cagé, Denis Cogneau, Nicolas Delalande, Isabelle Ferreras, Nancy Fraser, Sibylle Gollac, Yajna Govind, David Graeber, Julien Grenet, Stéphanie Hennette, Camille Herlin-Giret, Élise Huillery, Alexandra Killewald, Stephanie Kelton, Claire Lemercier, Noam Maggor, Ewan McGaughey, Dominique Meda, Eric Monnet, Pap Ndiaye, Martin O’Neill, Hélène Périvier, Fabian Pfeffer, Katharina Pistor, Patrick Simon, Alexis Spire, Pavlina Tcherneva, Samuel Weeks, Madeline Woker, Shoshana Zuboff, and many others whom I cannot cite here, but whose names and work will appear throughout the book.20
What are the main lessons that can be drawn from this new economic and social history? The most obvious is no doubt the following: inequality is first of all a social, historical, and political construction. In other words, for the same level of economic or technological development, there are always many different ways of organizing a property system or a border system, a social and political system or a fiscal and educational system. These options are political in nature. They depend on the state of power relationships between the various social groups and the worldviews involved, and they lead to inegalitarian levels and structures that are extremely variable, depending on societies and periods. All creations of wealth in history have issued from a collective process: they depend on the international division of labor, the use of worldwide natural resources, and the accumulation of knowledge since the beginnings of humanity. Human societies constantly invent rules and institutions in order to structure themselves and to divide up wealth and power, but always on the basis of reversible political choices.
The second lesson is that since the end of the eighteenth century there has been a long-term movement toward equality. This is the consequence of conflicts and revolts against injustice that have made it possible to transform power relationships and overthrow institutions supported by the dominant classes, which seek to structure social inequality in a way that benefits them, and to replace them with new institutions and new social, economic, and political rules that are more equitable and emancipatory for the majority. Generally speaking, the most fundamental transformations seen in the history of inegalitarian regimes involve social conflicts and large-scale political crises. It was the peasant revolts of 1788–1789 and the events of the French Revolution that led to the abolition of the nobility’s privileges. Similarly, it was not muted discussions in Paris salons but the slave revolt in Saint-Domingue in 1791 that led to the beginning of the end of the Atlantic slavery system. In the course of the twentieth century, social and trade-union mobilizations played a major role in the establishment of new power relationships between capital and labor and in the reduction of inequalities. The two world wars can also be analyzed as the consequence of social tensions and contradictions connected with the intolerable inequality that prevailed before 1914, both domestically and internationally. In the United States, it took a devastating civil war to put an end to the slavery system in 1865. A century later, in 1965, the Civil Rights movement succeeded in abolishing the system of legal racial discrimination (without, however, putting an end to discrimination that was illegal and nonetheless still very real). Examples are many: in the 1950s and 1960s the wars of independence played a central role in ending European colonialism; it took decades of riots and mobilizations to do away with South African apartheid in 1994, and so on.
In addition to revolutions, wars, and revolts, economic and financial crises often serve as turning points where social conflicts are crystallized and power relationships are redefined. The crisis of the 1930s played a central part in the long-lasting delegitimation of economic liberalism and the justification of new forms of state intervention. More recently, the financial crisis of 2008 and the worldwide Covid-19 pandemic in 2020–2021 have already begun to overturn various certainties that shortly before had been considered irrefutable, certainties concerning, for example, the acceptable level of public debt or the role of central banks. On a more local but still significant scale, the revolt of the gilets jaunes (“yellow vests”) in France in 2018 ended with the government’s abandonment of its plan to increase the carbon tax, which is particularly inegalitarian. At the beginning of the 2020s, the Black Lives Matter, #MeToo, and Fridays for Future movements are showing an impressive ability to mobilize people around racial, gender, and climatic inequalities, across national borders and generations. Taking into account the social and environmental contradictions of the current economic system, it is likely that such revolts, conflicts, and crises will continue to play a central role in the future, under circumstances that it is impossible to predict with precision. The end of history will not come tomorrow. The movement toward equality still has a long way to go, especially in a world in which the poorest, and particularly the poorest in the poorest countries, are preparing to be subjected, with increasing violence, to climatic and environmental damage caused by the richest people’s way of life.
It is also important to highlight another lesson issuing from history, namely that struggles and power relationships are not sufficient as such. They are a necessary condition for overturning inegalitarian institutions and established powers, but unfortunately they do not in any way guarantee that the new institutions and the new powers that will replace them will always be as egalitarian and emancipatory as we might have hoped.
The reason for this is simple. Although it is easy to denounce the inegalitarian or oppressive nature of established institutions and governments, it is much harder to agree on the alternative institutions that will make it possible to make real progress toward social, economic, and political equality, while at the same time respecting individual rights, including the right to be different. The task is not at all impossible, but it requires us to accept deliberation, the confrontation of differing points of view, compromises, and experimentation. Above all, it requires us to accept the fact that we can learn from the historical trajectories and experiences of others, and especially that the exact content of just institutions is not known a priori and is worth debating as such. Concretely, we will see that since the end of the eighteenth century, the march toward equality has been based on the development of a number of specific institutional arrangements that have to be studied as such: equality before the law; universal suffrage and parliamentary democracy; free and obligatory education; universal health insurance; progressive taxes on income, inheritance, and property; joint management and labor law; freedom of the press; international law; and so on.
However, each of these arrangements, far from having reached a complete and consensual form, is connected with a precarious, unstable, and temporary compromise, in perpetual redefinition and emerging from specific social conflicts and mobilizations, interrupted bifurcations, and particular historical moments. They all suffer from multiple insufficiencies and must be constantly rethought, supplemented, and replaced by others. As it currently exists almost everywhere, formal equality before the law does not exclude profound discriminations based on origins or gender; representative democracy is only one of the imperfect forms of participation in politics; inequalities of access to education and health care remain extremely intractable; progressive taxes and redistribution of wealth must be completely reconceived on the domestic and international scale; power-sharing in business enterprises is still in its infancy; control of almost all the media by a few oligarchs can hardly be considered the most complete form of a free press; the international legal system, founded on the uncontrolled circulation of capital without any social or climatic objective, is usually related to a kind of neocolonialism that benefits the wealthiest people, and so on.
To continue to shake up and redefine established institutions, crises and power relations are necessary, as was the case in the past, but we will also need processes of learning and collective engagement, as well as mobilization around new political programs and proposals for new institutions. This requires multiple frameworks for the discussion, elaboration, and diffusion of knowledge and experiences: political parties and labor unions, schools and books, travel and meetings, newspapers and electronic media. The social sciences naturally have a role to play in this, a significant role, but one that must not be exaggerated: the processes of social adaptation are the most important. Above all, this adaptation also involves collective organizations, whose forms themselves remain to be reinvented.
In sum, two symmetrical pitfalls must be avoided: one consists in neglecting the role of struggles and power relationships in the history of equality. The other consists, on the contrary, in sanctifying and neglecting the importance of political and institutional outcomes along with the role of ideas and ideologies in their elaboration. Resistance by elites is an ineluctable reality today, in a world in which transnational billionaires are richer than states, much as in the French Revolution. Such resistance can be overcome only by powerful collective mobilizations during moments of crisis and tension. Nonetheless, the idea that there is a spontaneous consensus regarding equitable and emancipatory institutions, and that breaking elites’ resistance would be sufficient to put these institutions in place, is a dangerous illusion. Questions regarding the organization of the welfare state, the recasting of the progressive income tax and international treaties, postcolonial reparations, or the struggle against discrimination are both complex and technical and can be overcome only through a recourse to history, the diffusion of knowledge, deliberation, and confrontation among differing points of view. Social class, no matter how important, does not suffice to forge a theory of a just society, a theory of property, a theory of borders, of taxation, of education, of wages and salaries, or of democracy. For any particular social experience, there will always be a form of ideological indetermination, on the one hand because class is itself plural and multidimensional (status, property, income, diplomas, gender, origin, and so on), and on the other because the complexity of the questions asked does not allow us to suppose that purely material antagonisms could lead to a single conclusion regarding equitable institutions.
The experiment of Soviet communism (1917–1991), a major event that runs through and to a certain extent defines the twentieth century, perfectly illustrates these two pitfalls. On the one hand, it was in fact power relationships and intense social struggles that allowed the Bolshevik revolutionaries to replace the czarist regime with the first “proletarian state” in history, a state that initially achieved considerable advances in education, public health, and industry, while at the same time making a major contribution to the victory over Nazism. Without the pressure of the Soviet Union and the international communist movement, it is not at all certain that the Western property-owning classes would have accepted Social Security and progressive income taxes, decolonization and civil rights. On the other hand, the sanctification of power relationships and the Bolsheviks’ certainty that they knew the ultimate truth concerning equitable institutions led to the totalitarian disaster we witnessed. The institutional arrangements put in place (a single political party, bureaucratic centralization, hegemonic state property, and a rejection of cooperative property, elections, labor unions, and so on) claimed to be more emancipatory than bourgeois or social-democratic institutions. They led to levels of oppression and imprisonment that completely discredited this regime and ultimately caused its fall, while at the same time contributing to the emergence of a new form of hypercapitalism. That is how, after being in the twentieth century the country that had entirely abolished private property, Russia became at the beginning of the twenty-first century the world capital of the oligarchs, financial opacity, and tax havens. For all these reasons, we have to examine closely the genesis of these different institutional arrangements, just as we have to study the institutions set up by Chinese communism, which might prove more durable, though no less oppressive.
I have sought to avoid these two pitfalls: power relationships must be neither ignored nor sanctified. Struggles play a central role in the history of equality, but we must also take seriously the question of equitable institutions and egalitarian deliberation about them. It is not always easy to find a balanced position between these two points: if we overemphasize power relationships and struggles, we can be accused of yielding to Manichaeism and neglecting the question of ideas and content; conversely, by focusing attention on the ideological and programmatic weaknesses of the egalitarian coalition, we can be suspected of further weakening it, and underestimating the dominant classes’ ability to resist and their short-sighted egoism (which is, however, often patent). I have done my best to escape these two pitfalls, but I am not sure I have always succeeded, and I beg my readers’ indulgence in advance. Above all, I hope the historical and comparative materials presented in this book will be useful in clarifying the nature of a just society and the institutions that compose it.
1. K. Pomeranz, The Great Divergence: China, Europe and the Making of the Modern World Economy (Princeton, NJ: Princeton University Press, 2000).
2. F. Braudel, Civilization and Capitalism, 3 vols., trans. Siân Reynold (New York: Harper and Row, 1982–1984); I. Wallerstein, The Modern World-System, 4 vols. (New York: Academic Press, 1974–1989).
3. P. Parthasarathi, Why Europe Grew Rich and Asia Did Not: Global Economic Divergence 1600–1850 (Cambridge: Cambridge University Press, 2011); S. Beckert, Empire of Cotton: A Global History (New York: Alfred A. Knopf, 2014); S. Beckert and S. Rockman, Slavery’s Capitalism: A New History of American Economic Development (Philadelphia: University of Pennsylvania Press, 2016); J. Levy, Ages of American Capitalism: A History of the United States (New York: Random House, 2021).
4. See, for example, F. Cooper, Citizenship between Empire and Nation: Remaking France and French Africa 1945–1960 (Princeton, NJ: Princeton University Press, 2014); C. Hall, N. Draper, K. McClelland, K. Donington, and R. Lang, Legacies of British Slave-Ownership: Colonial Slavery and the Formation of Victorian Britain (Cambridge: Cambridge University Press, 2014); O. Rosenboim, The Emergence of Globalism: Visions of World Order in Britain and the United States 1939–1950 (Princeton, NJ: Princeton University Press, 2017); E. Saada, Les Enfants de la colonie. Les métis de l’empire français, entre sujétion et citoyenneté (Paris: La Découverte, 2007); P. Singaravélou and S. Venayre, eds., Histoire du monde au XIXe siècle (Paris: Fayard, 2017); S. Subrahmanyam, Empires between Islam and Christianity, 1500–1800 (Albany, NY: SUNY Press, 2019); A. Stanziani, Les Métamorphoses du travail contraint. Une histoire globale, XVIIIe–XIXe siècles (Paris: Presses de Sciences Po, 2020).
5. H. Zinn, A People’s History of the United States (1980; New York: Harper, 2009); M. Zancarini-Fournel, Les Luttes et les Rêves. Une histoire populaire de la France de 1685 à nos jours (Paris: La Découverte, 2016); G. Noiriel, Une histoire populaire de la France de la guerre de Cent Ans à nos jours (Marseille: Agone, 2018); D. Tartakowsky, Le pouvoir est dans la rue. Crises politiques et manifestations en France, XIXe–XXe siècles (Paris: Aubier, 1998); B. Pavard, F. Rochefort, and M. Zancarini-Fournel, Ne nous libérez pas, on s’en charge! Une histoire des féminismes de 1789 à nos jours (Paris: La Découverte, 2020).
6. T. Piketty, Capital in the Twenty-First Century (Cambridge, MA: Belknap Press of Harvard University Press, 2014), 3–11, 229–230.
7. E. Labrousse, Esquisse du mouvement des prix et des revenus en France au XVIIIe siècle (Paris: Dalloz, 1933). Compare A. Chabert, Essai sur les mouvements des prix et des revenus en France de 1798 à 1820 (Paris: Librairie de Medicis, 1949), which documents an increase in wages during the Revolution and the Empire.
8. J. Bouvier, F. Furet, and M. Gilet, Le Mouvement du profit en France au XIXe siècle. Matériaux et études (Paris: Mouton, 1965).
9. M. Bloch, Les Caractères originaux de l’histoire rurale française (Paris: Armand Colin, 1931).
10. A. Daumard, Les Fortunes françaises au XIXe siècle. Enquête sur la répartition et la composition des capitaux privés à Paris, Lyon, Lille, Bordeaux et Toulouse d’après l’enregistrement des déclarations de successions (Paris: Mouton, 1973).
11. In addition to the works already cited, see F. Simiand, Le Salaire, l’Évolution sociale et la Monnaie (Paris: Alcan, 1932); C. Baudelot and A. Lebeaupin, Les Salaires de 1950 à 1975 (Paris: INSEE, 1979); J. Goy and E. Le Roy Ladurie, Les Fluctuations du produit de la dîme. Conjoncture décimale et domaniale de la fin du Moyen Âge au XVIIIe siècle (Paris: Mouton, 1972); G. Postel-Vinay, La Terre et l’Argent. L’agriculture et le crédit en France du XVIIIe siècle au début du XXe siècle (Paris: Albin Michel, 1998); J. Bourdieu, L. Kesztenbaum, and G. Postel-Vinay, L’Enquête TRA. vol. 1: 1793–1902: histoire d’un outil, outil pour l’histoire (Paris: Institut national d’études démographiques, 2013).
12. S. Kuznets, Shares of Upper Income Groups in Income and Savings (Cambridge MA: National Bureau of Economic Research, 1953).
13. R. J. Lampman, The Share of Top Wealth-Holders in National Wealth, 1922–56 (Princeton NJ: Princeton University Press, 1962).
14. A. B. Atkinson and A. J. Harrison, Distribution of Personal Wealth in Britain (Cambridge: Cambridge University Press, 1978).
15. A. H. Jones, American Colonial Wealth: Documents and Methods (New York: Arno Press, 1977).
16. T. Piketty, Les Hauts Revenus en France au XXe siècle (Paris: Grasset, 2001); and then A. B. Atkinson and T. Piketty, Top Incomes over the 20th Century (Oxford: Oxford University Press, 2007); and A. B. Atkinson and T. Piketty, Top Incomes: A Global Perspective (Oxford: Oxford University Press, 2010).
17. The World Inequality Database was initially created in 2011 under the name “World Top Incomes Database,” before taking its current name with the publication in French and then in English of F. Alvaredo, L. Chancel, T. Piketty, E. Saez, and G. Zucman, World Inequality Report 2018 (Cambridge, MA: Belknap Press of Harvard University Press, 2018).
18. Piketty, Capital in the Twenty-First Century; T. Piketty, Capital and Ideology (Cambridge, MA: Belknap Press of Harvard University Press, 2020).
19. A. Gethin, C. Martínez-Toledano, and T. Piketty, eds., Political Cleavages and Social Inequalities: A Study of Fifty Democracies, 1948–2020 (Cambridge, MA: Harvard University Press, 2021). Compare S. Lipset and S. Rokkan, “Cleavage Structures, Party Systems and Voter Alignments: An Introduction,” in Party Systems and Voter Alignments: Cross-national Perspectives, ed. Lipset and Rokkan (New York: Free Press, 1967).
20. The complete references will be given as they are used.