Beauty Pays: Why Attractive People are More Successful. By Daniel Hamermesh. Princeton University Press; 216 pages; $24.95 and £16.95. Buy from Amazon.com, Amazon.co.uk

The Beauty Bias: The Injustice of Appearance in Life and Law. By Deborah Rhode. Oxford University Press USA; 272 pages; $17.95 and £15.99. Buy from Amazon.com, Amazon.co.uk

Honey Money: The Power of Erotic Capital. By Catherine Hakim. Allen Lane; 304 pages; £20. To be published in America in September as “Erotic Capital: The Power of Attraction in the Boardroom and the Bedroom” by Basic Books; $26. Buy from Amazon.com, Amazon.co.uk

FRANCE looked back this week at the 1911 theft of the Mona Lisa from the walls of the Louvre. It was one of the most startling art heists in history, but the emotions it still arouses go beyond that. Stealing Leonardo da Vinci's painting was like stealing beauty itself. And beauty has lost none of its power to bewitch, bother and get its own way, as three new books on the economic advantages of good looks confirm.

Physically attractive women and men earn more than average-looking ones, and very plain people earn less. In the labour market as a whole (though not, for example, in astrophysics), looks have a bigger impact on earnings than education, though intelligence—mercifully enough— is valued more highly still.

Beauty is naturally rewarded in jobs where physical attractiveness would seem to matter, such as prostitution, entertainment, customer service and so on. But it also yields rewards in unexpected fields. Homely NFL quarterbacks earn less than their comelier counterparts, despite identical yards passed and years in the league. Not everything comes easier: good-looking women seeking high-flying jobs in particularly male fields may be stymied by the “bimbo effect” until they prove their competence and commitment. But the importance of beauty in the labour market is far more pervasive than one might think.

The same is true in other markets. Women have traditionally traded looks for economic support in marriage. A Chinese study confirms that the husbands of unappealing women earn about 10% less than those of their dishier counterparts. Attractive people also have an easier time getting a loan than plain folks, even as they are less likely to pay it back. They receive milder prison sentences and higher damages in simulated legal proceedings. In America more people say they have felt discriminated against for their appearance than because of their age, race or ethnicity. Pretty people, it seems, have all the luck. These books attempt to explain why that is, and what, if anything, should be done about it.

Daniel Hamermesh, an economist at the University of Texas, has long written about “pulchronomics”. In “Beauty Pays” he reckons that, over a lifetime and assuming today's mean wages, a handsome worker in America might on average make $230,000 more than a very plain one. There is evidence that attractive workers bring in more business, so it often makes sense for firms to hire them. Whether rewarding them accordingly—and paying their less attractive peers more stingily—is good for society is another matter.

In examining the case for legal protection for the ugly, Mr Hamermesh relies to a degree on the work of Deborah Rhode, a law professor at Stanford University and author of “The Beauty Bias”. Ms Rhode clearly struggles to see why any woman would willingly embrace fashion (particularly high heels). She is outraged that virtually all females consider their looks as key to their self-image. She cites a survey in which over half of young women said they would prefer to be hit by a truck than be fat. Her indignation is mostly moral. Billions of dollars are now spent on cosmetic surgery—up to 90% of it by women—at a time when almost a fifth of Americans lack basic health care. The more women focus on improving their looks, Ms Rhode argues, the less they think about others.

Discriminating against people on the grounds of personal appearance should be banned, she says. It limits a person's right to equal opportunity, reinforces the subordination of groups where unappealing characteristics, including obesity, are concentrated (ie, the poor, some ethnic minorities), and restricts self-expression. Yet because ugliness is harder to define than race or sex, some argue that anti-discrimination laws are impossible to maintain. And anyway, say employers, appearance is often relevant to the job at hand.

Ms Rhode sees the hurdles, but argues that they can be dealt with. In places where “lookism” is already prohibited (eg, Washington, DC), such statutes have not provoked a flood of frivolous cases, she says. Occasionally beauty is essential to a business (ie, modelling, but not air-hostessing). But concerns about an employee's effectiveness often reflect the biases of employers, not customers. Laws influence attitudes over time, she says, by denying those with prejudices the opportunity to indulge them.

“Honey Money”, Catherine Hakim's provocative book, is a different kettle of fish. Where Mr Hamermesh and Ms Rhode see discrimination, she sees an opportunity for women to enhance their power “in the bedroom and the boardroom”. She argues that “erotic capital” is an underrated class of personal asset, to set beside economic capital (what you have), human capital (what you know) and social capital (who you know). Ms Hakim attempts to quantify a complex mix of physical and social assets, consisting of beauty, sex appeal, self-presentation, social skills, liveliness and sexual competence. Like other sorts of capital, the erotic kind is important for success; but unlike others it is largely independent of birth and class. It is especially valuable for poor people, young people, the newly arrived and the otherwise unqualified. In heterosexual settings it belongs primarily to women.

Ms Hakim suggests that women have more erotic capital than men to start with, mainly because they have had to work at it for centuries. But women have the erotic upper hand for another reason: the male “sexual deficit”. Despite the fact that both sexes are more sexually active than ever before, from the age of about 30 women's libido tends to fall off while men's does not. Because women have less interest in sex than men, it is, to put it crudely, a seller's market. In the power dynamic of couples, controlling access to sex is more important than earning more money, says Ms Hakim. It is the woman's main bargaining chip, as most still earn less than their partners. Feminists who want women to throw away their femininity are overlooking a powerful asset, Ms Hakim argues.

This is controversial stuff. Even those who reject the notion that women are just not that into sex can support Ms Hakim's call for the full legalisation of prostitution and surrogate pregnancies for profit, thus giving women the freedom to earn a return on whichever personal asset they choose.

All three authors are in or fast approaching their 60s. They are contemporaries of the generation of feminists who waged war against the beauty culture, leaving unshaved legs and allegedly burned bras in their wake. But life has moved on. Sexualised images are everywhere, and the world that has emerged is one in which no one can afford to pretend beauty does not matter. Men too, having lost their monopoly of well-paid jobs, are investing in their erotic capital to enhance their appeal to mates and employers. They are marching off to gyms and discovering face cream in record numbers. Perhaps this explains Mona Lisa's bemused smile. She knew what was coming.