This is a really short book, less than 100 pages, which pages are not even full-size to begin with. I read it on a flight from Miami to New York and still had time to do the "hard" Sudoku puzzle in the airline magazine.
But it is well worth reading. Simply stated, the author,a professor of philosophy at Princeton who previously wrote a popular book called "On Bullsh*t" bluntly rejects the pursuit of economic equality as a morally valid goal. He characterizes such a pursuit as "alienating" a person from his or her own self, by defining said person by reference to what others have or lack. Using economic equality to define a person's moral status means that if one has more income or wealth than others, one should feel guilt, and if one has less, one should feel victimized. This means that people can not be satisfied or happy based on their personal assessment of their own lives and that is why he defines the economic equality frame as "alienating". For some reason I don't quite understand, he eschews use of words like "envy", "jealousy" or "covetousness" to describe that state of mind.
He also discusses attempts to justify economic equality based on the theory of "diminishing marginal utility" which postulates that the marginal value of an additional dollar to a person who is already well off is less than to a person who has substantial needs. First, he notes, that such an argument is really an argument for a basic level of sufficiency, not ultimate equality. Once both persons have a sufficient amount, and what is being compared is two persons' desire to purchase a discretionary item, the proposition is not credible. The marginal utility of moving from an income level that uses frequent flyer to upgrade to first class to the income level that uses private jets may be huge, because it enables one to bypass the TSA nightmare and spares one unnecessarily long waits in airports.
In the same vein, he disputes the measurability and comparability of marginal utilities ab initio. He astutely offers the example of series of things -- products, services and content. Think about collecting (e.g., comic books, baseball cards, first editions). Or watching a TV series, such as Breaking Bad or the Sopranos: how important was it to see the last episode vs one in the middle? Or the greater value of attending the championship game at the end of a season. In each case, the last purchase or experience in the series can be the most desired, not the least valued. Life can't be reduced to simple formulas with linear slopes. Merely because marginal utility can be observed in hindsight or across a population as a whole does not mean it can be predicted with accuracy as regards the future or any given individual. See "ecological fallacy".
There is also the fact, not raised by the author, of differing life cycles of consumption, work and leisure. One person may work extra hard in high school, college, and his or her prime working years, and may save aggressively. with the goal of consolidating a large block of leisure and savings in retirement. Another person may elect to enjoy a more dispersed leisure throughout those earlier periods and find himself or herself working later in life to make up for it. Think of the famous marshmallow experiment. But how does one justly define, at any point along the timelines of these two lives, what is "equality" between them?
The two most significant lines of criticism of the "equality" imperative that are missing from this book are the impact on child-rearing and the failure to account for disparities in work and productivity.
Regarding child-rearing, a world of perfect equality dis-incentivizes parents from investing extra time or resources in their children, given that any fruits of above-average development of the child will not be retained by the child, let alone benefit the parents indirectly, but instead disseminated among the population to maintain equality. So why expend extra effort?
Regarding work, a demand for outcome equality in a world where people have unequal inputs of talent and work ethic, are unequally clever and productive, and make decisions of unequal merit and wisdom, merely substitutes one form of inequality for another, disparately coercing the best workers, the most productive, the most in demand, dramatically more than the least, unwisely alienating those who make the greatest contribution to the society and invariably incentivizing those in the middle to work less and under-develop their productivity in reliance on the prospect of receiving transfers of the surplus generated by the most productive. In Lincoln's famous remark, "It is the eternal struggle between these two principles -- right and wrong -- throughout the world. They are the two principles that have stood face to face from the beginning of time, and will ever continue to struggle. The one is the common right of humanity and the other the divine right of kings. It is the same principle in whatever shape it develops itself. It is the same spirit that says, "You work and toil and earn bread, and I'll eat it.". To achieve perfect equality among a population with different talents and efforts requires the extermination of that population's freedom to act in ways that generate unequal outcomes. Thus, the only place where there is perfect economic equality is a cemetery.
Last, the contingency of the "equality" demand should be remarked upon. It is, with rare exceptions, not proposed on a global basis, among all people, as one would expect a moral principle, such as "thou shalt not kill" to be laid out. It is analyzed and demanded, state-by-state, and is thus contingent on borders. Scandinavian nations are "good" and "more just" because they have less inequality among their population than the US, which is "mean" and "unjust" because it has greater inequality among its population. That the Scandinavian nations are highly unequal compared to sub-saharan Africa is somehow not considered of great relevance to moral inquiry. That the US has many more immigrants and first-generation residents is rarely considered. It is tremendously incoherent that the proponents of "equality" accord borders, which are artifices of humans and thus malleable, as givens that frame their moral analysis, while more fundamental and natural facts, such as differences in talents and effort, are disregarded entirely. The demand for "equality" should be recognized not as a moral demand but a political one, when it is confined to the outcomes of the population within a given polity.