Two gray-haired men from Tokyo Medical University bowed their heads in shame before the assembled media in early August. An internal inquiry into one curious case — how did a government official’s son gain admission despite doing poorly on the entrance exam? — had exposed a pattern of fraud and discrimination. For more than a decade, investigators found, the school had systematically altered entrance-exam scores to restrict the number of female students and to award admission to less-qualified male applicants. The supposed rationale, that female doctors are prone to leave the profession after marriage or childbirth, only inflamed a national debate on gender inequality. The school initially denied any knowledge of the wrongdoing, but one of the bowing men — Tetsuo Yukioka, who happened to be chairman of the school’s diversity promotion panel — offered an oblique explanation: “I suspect that there was a lack of sensitivity to the rules of modern society.”

A century and a half after opening up, Japan is now one of the planet’s most advanced, affluent and democratic countries. But in one key respect, it has remained stubbornly regressive: Japanese women, to a degree that is striking even by the lamentable standards of the United States and much of the rest of the world, have been kept on the margins of business and politics. Five years ago, the Japanese prime minister, Shinzo Abe, vowed to create what he describes as “a society where women can shine.” Falling birthrates had left Japan with one of the world’s oldest and fastest-shrinking labor forces. (The population from ages 15 to 64 is expected to plummet to 45 million in 2065 from 76 million in 2017.) Rather than open the gates to immigration, an unpopular solution in insular Japan, Abe embraced a plan to ease the way for millions of married and middle-aged women to return to work. The effort, Abe said, was “a matter of the greatest urgency.”

The nickname for Abe’s program, “womenomics,” originated with Kathy Matsui, the vice chairwoman of Goldman Sachs Japan. Matsui, a Japanese-American who has lived in Japan on and off for more than three decades, told me she became aware of women’s underutilized economic potential soon after the birth of her first child during the stagnant 1990s. “A lot of my ‘mama’ friends were not returning to the work force to the extent that I assumed,” she recalled. “I realized that maybe the growth solution for Japan was right in front of my face.” After Abe adopted “womenomics” in 2013, Matsui predicted that the plan could add 7.1 million employees and lift Japan’s gross domestic product by nearly 13 percent. Activists and scholars were skeptical — the breathless calculations seemed to underplay the institutional sexism that pervades Japanese society — but Matsui credits Abe with depoliticizing the debate. “He moved the issue of diversity out of the realm of human rights into the realm of economic growth,” Matsui says.

The correlation between the advancement of women and increased development rates follows a simple logic: More working women means more growth, especially in rapidly aging societies, where their participation alleviates the impact of a shrinking labor force. And a more inclusive economy can create ripple effects, expanding the talent pool, forming a more skilled work force and putting more money in the hands of women. In Japan, the ultimate hope was that women would no longer be faced with the cruel choice between remaining single (to pursue a career among men) or having a family (and giving up a career). “With this one stone, we could hit three or four birds,” says Rui Matsukawa, a legislator and member of Abe’s Liberal Democratic Party and mother of two. “It was like a survival strategy.”