As a topic of mainstream media discussion, inequality has gained currency in the years since the global economic crisis began in 2008. Perhaps the most striking sign of interest in inequality is the success of economist Thomas Piketty’s Capital in the Twenty-First Century, a 700-page book on the distribution of wealth that topped bestseller lists in 2014.

Most of the discussion focuses on inequality of incomes and/or wealth, and it is rare to see “inequality” defined as a concept. Instead, the meaning of the term is defined by whatever indicator is cited—the share of wealth of the top 1 percent of households compared to that of the bottom 20 percent, for example. Most often relied upon is the Gini coefficient of national income distribution. The Gini coefficient is a formula yielding a measure of income inequality with 0 representing perfect equality (everyone in the measured country having the same income) and 1.0 representing perfect inequality (one individual in the measured country has all the income).

There are Gini coefficients for disparity in educational attainment and for “opportunity,” but these are used much less frequently than the coefficient for income. Life expectancy and infant mortality are often used to demonstrate inequality of health and health care between different racial or ethnic groups within a particular country, but rarely as part of a broad conversation about inequality and the many ways it manifests itself.

Göran Therborn, a retired professor of sociology at Cambridge University, makes an important contribution in The Killing Fields of Inequality. Therborn states his two aims as being “to convince students and academic colleagues of the necessity of a multidimensional and global approach to inequality; and, above all, to raise concern about existing multiple kinds of inequality, and to promote commitment to equalization among my fellow citizens of the world.” In setting out to address two very distinct audiences—students and academics in his first objective and “citizens of the world” in his second—Therborn is ambitious. He is also far more successful in formulating arguments for the aim of promoting a multidimensional, multinational approach to inequality in academic study than he is in articulating an argument around which to build activism for equality.

When Therborn says “inequality kills,” he’s not just stating that inequality results in deprivation of the necessities of life. He believes that inequality itself results in “psychosomatic consequences of different class or status situations.” Several times, he refers to data from a longitudinal study of civil servants in the United Kingdom showing that life expectancy correlates to civil service grade irrespective of controls for lifestyle factors such as tobacco and alcohol use, and other studies showing correlations between specific diseases and social status, again controlling for other risk factors.

Therborn constructs something of a taxonomy of inequality, identifying categories and effects of inequality, as well as mechanisms of equality and inequality. He works off the economist Amartya Sen’s basic definition of equality as being “equality of capability to function fully as a human being,” a definition broad enough to encompass access to health care and education, protection from environmental hazards, distribution of resources, and political freedom.

Therborn differentiates inequality into three categories. “Vital inequality” refers to “socially constructed unequal life chances of human organisms.” Vital inequality is measured by such data points as life expectancy, infant mortality, and incidence rates of malnutrition. “Existential inequality” refers to “unequal allocation of personhood,” because of discrimination and oppression based on race, gender, gender or sexual identity, disability, or other invidious distinctions. “Resource inequality” refers to “providing human actors with unequal resources to act,” and encompasses the most common formulations of income and wealth distribution.

The categories are not discreet—each has “sending” and “receiving” interactions with the others. Existential inequality has a sending effect in locking people into resource inequality, which in turn has a sending effect on vital inequality. The categories can move independently, however.

Therborn also sorts the effects of inequality into categories. He refers to “sundering,” the tearing apart of societies, and to “squandering,” the dissipation of resources and productive capacity by the privileged few, and to “dictat-ship,” the imposition of control by those with resources and privileged status.

The final sets of categories are four “mechanisms” of inequality, and corresponding mechanisms of equality. “Distantiation” refers to the creation of “winners and losers” based on starting position and privileges, which has the social effect of widening the distance in individual achievement. Corresponding to that are efforts at “approximation” to attempt to close those gaps through policies such as affirmative action. Other counterposed mechanisms are “exclusion/inclusion”—barring the advance of groups of people or removing barriers to advancement; “hierarchization/dehierarchization”—building or flattening a hierarchy of power; and “exploitation/redistribution and rehabilitation”—extracting value from those at the bottom for the benefit of those at the top or redistributing from those at the top to those at the bottom. Each is interactive with other mechanisms, and each has differing relationships to the categories of inequality.

Unfortunately, in the brief discussion of his taxonomy, roughly 1/5 of a work of only 184 pages, Therborn does not adequately develop all the categories he defines. While he is undeniably correct in stating that existential inequality has been reduced to a much greater extent globally than resource or vital inequality, he doesn’t define existential inequality clearly enough to determine exactly where he places de facto inequality remaining after the removal of formal barriers. It’s also difficult to say with certainty how he would distinguish policies of approximation from policies of inclusion. Some assertions are also left unexplained. He describes collective bargaining and union rights as a mechanism of equality, which is fair enough, but then goes on to say they operate through dehierarchization. That seems less obvious, and it’s difficult to evaluate given the lack of any real explanation of what he means.

Similarly, Therborn reviews data at a bewildering pace, sometimes summarizing six or more indicators on a single page. Unless a reader is familiar with the data, it can be extremely difficult to assess the significance of each data point, or at times even to understand why he relates it to one type of inequality rather than another.

Nevertheless, there is considerable value in Therborn’s framework for thinking about inequality, and he makes his case for a multidimensional approach. His description of sending and receiving interactions is useful, and provides an alternative to simply finding correlations between disparate indicators. His framework also provides a means of making fluid connections between a range of circumstances in fashioning a narrative about the effects of inequality.

Taking a public health issue Therborn doesn’t mention, for example, one can easily connect the high incidence of post-traumatic stress among Palestinian children in the Occupied Territories—about one in three, according to a 2005 study^*—to the oppression imposed by an apartheid regime which devalues the lives of Palestinian children. There is nothing new in connecting the damage inflicted on Palestinian children to inequality, but Therborn’s framework provides a vocabulary to more concisely show the relationship of different manifestations of inequality in terms of interactive causation rather than linear cause and effect. Post-traumatic stress among children results from the experiences of existential inequality, and results in delays and interference with the ability to learn and develop higher-order thinking—the imposition of vital inequality. Vital inequality aggravates the resource inequality of apartheid by reducing productive capacity, and vital and resource inequality may also reduce capacity to reduce existential inequality.

The second part of the book treats inequality historically. Therborn looks at the position of three “masters” on inequality in modern history. Alexis de Tocqueville saw falling inequality as a theme of modernity. Karl Marx saw inequality rising with the establishment of industrial capitalism. Writing in the mid-twentieth-century United States, economist Simon Kuznets found inequality rising under industrial capitalism and then beginning to fall in the twentieth century. After 1980, the trend has been a return to rising inequality, and Therborn reviews various reasons for the reversal. Much of this is familiar, but sometimes he offers intriguing insights, including the assertion that one reason for rising vital inequality in rich nations is that the ruling class is no longer subject to waves of concern over the fitness of the working class for military service because of the “current substitution of mercenary high-tech armies for the mass armies of the industrial age.”

The final section of the book is the most challenging for Therborn, as he turns to efforts to roll back rising inequality. In one more list, Therborn says that there are three institutions through which inequality is transmitted—family, capitalism, and nation. Family transmits inequality through class-based marriage patterns and by providing better opportunity for the rich to influence their children’s education and learning environment. Capitalism transmits inequality through exploitation and division into owners of capital and sellers of labor power. Nations, while they can embrace mechanisms of equalization, have become almost exclusively transmitters of inequality in order to attract capital and maintain competitive position. The distinction is confusing, in that it’s unclear why Therborn offers the modern family and state as institutions of inequality separate from—rather than shaped by—capitalism. Interestingly, his description of how the family transmits inequality is consistent with Marxist social reproduction theory, and his characterization of the nation is consistent with Marxist thought on international competition.

He talks about efforts to promote equalization through education and a notion of citizenship rights that would reform nations, as though these are separate from the effort to teach capitalism and capitalists “how to behave.” Ultimately, he favors what he calls “egalitarian capitalism.” Acknowledging that egalitarian capitalism has been in retreat for more than three decades in the rich “core of capitalism” where it had its greatest success, Therborn is heartened by a rising tide of egalitarianism in Latin America bucking the global trend. He really offers no support for the implicit suggestion that capitalism can be reformed by ideological egalitarianism.

Therborn argues that the laboring classes will be less decisive than in past struggles, and that the “chances of equality will hinge primarily . . . on the orientation of the Middle Classes.” Broadly defined as neither rich nor poor, the middle class will drive development in Asia, Latin America, and Africa, and has the potential to rebel against “the social cost of other people’s misery” and the “illegitimacy” of oligarchy. According to Therborn, the middle class will feel constrained in their freedom by “walled-in seclusion, barbed wire and armed bodyguards,” and will be repulsed by the values and behavior of the very rich. They will extend their sympathy and eventually their active support to the movements and struggles of the working class.

The value of The Killing Fields of Inequality lies not in Therborn’s formulation of a middle-class ideology of egalitarianism, but in his development of a useful classification scheme for characterizing inequality by type and interactive effect. In so doing, he has contributed to a discussion of inequality that can move relatively smoothly among indicators and that can promote an expansive view of the manifestations of inequality.

*    Vivian Khamis, “Post-Traumatic Stress Disorder among School Age Palestinian Children,” Child Abuse and Neglect 29, no. 1 (January 2005): 81-85.