China still faces yawning gaps in wages and employment between men and women, according to surveys. But women made up more than half of undergraduate students in 2014, compared with about 46 percent a decade earlier, and accounted for nearly half of graduate students, government figures show.

Cheng Guping, a 30-year-old from Hangzhou in eastern China who works at a start-up and is pursuing a doctorate in economics, is one of those women. She cited her professional and educational obligations as the reason she and a recent boyfriend broke up. “I felt that our level of affection wasn’t enough yet,” she said. “I want to see how far I can go on my own.”

Suitable mates are simply hard to find, said Ms. Cheng, who describes many men her age as “not mature or irresponsible.” Referring to another former boyfriend, she said: “When we wanted to do something, or go for food, he only liked to act cute and say with a smile, ‘We’ll do whatever you like.’ It made me feel like I had a son.”

Businesses are preparing for the shift. The jewelry industry expects sales growth to slow in China as marriage declines. In response, many stores are offering a greater variety of jewelry, such as cheaper gems to entice dating couples who have less money.

“Even though they are not getting married,” said Annie Yau Tse, the chief executive of Tse Sui Luen, a jewelry chain based in Hong Kong, “people still need someone to be with them, and they still want love.”