The ideal worker at the Chinese chemical manufacturer, according to the internal memo, is hardworking, virtuous and loyal. And — perhaps most important — willing to have children for the good of the country.

That was the message that the company, Shandong Shuntian Chemical Group, sent to unmarried employees recently, in a notice that spread widely on social media. It instructed them to start families by Sept. 30, or else.

“If you cannot get married and start a family within three quarters, the company will terminate your labor contract,” the memo said.

Shandong Shuntian was not the first company to try to dictate its employees’ personal lives amid rising concern about China’s plummeting marriage and birth rates. Weeks earlier, a popular supermarket chain had told its staff not to ask for betrothal gifts, to lower the cost of weddings.

Both orders were widely criticized, for many of the same reasons that people are refusing to start families in the first place. Besides the economic cost of having children, many young Chinese cite a desire for personal autonomy. They reject the traditional idea that their families should direct their lives, and they certainly aren’t inclined to let their employers have a say.

Last year, 6.1 million Chinese couples got married — a 20 percent decline from a year earlier, and the fewest since the government began releasing statistics in 1986. China’s population has fallen for three straight years.