The U.S. Census Bureau is proposing to eliminate a series of questions about marital history from its ongoing American Community Survey, now the only reliable source of information on marriage and divorce rates in the United States.

Demographers and sociologists are asking the Census Bureau to keep the questions, pointing out that if they are dropped, the United States will become the only country in the developed world that does not generate annual age-specific rates of marriage and divorce, and would lose its only reliable measure of divorce rates.

“It’s an example of the federal statistical system breaking down,” said Steve Ruggles, director of the Minnesota Population Center.

One of the questions up for elimination — “In the past 12 months did this person get married?” — was first asked in 1850, said Ruggles, a historian at the University of Minnesota who studies divorce and marriage. He says the questions and what they tell us about society are irreplaceable, and now more necessary than ever.

“The drop in marriage among young people is just extraordinary. I’m projecting that about a third of the people who are currently 20 to 24 years old are never going to get married, and that’s completely unprecedented in American history,” Ruggles said. “So this is a bad time to stop collecting any data on it. It’s an amazing transformation.”

The survey, sent annually to about 3 million U.S. households, asks whether in the past 12 months a person has been married, widowed or divorced. It also asks how many times a person has been married and what year they were last married, which gets at how long American marriages last.

Those five questions about marital history are among seven on the chopping block as the Census Bureau tries to cut costs.

Since the answers to the marital history questions come with information on the age, race, education and income level of the people divorcing or getting married, they allow demographers to analyze divorce and marriage rates in connection with a series of economic and cultural factors.

Researchers are able to figure out divorce rates by ethnic group, or by education. Sociologists use the data to investigate divorce rates and marriage duration during recessions, or in states with different levels of religious conservatism. They can come up with millennial divorce rates in the top 25 cities.

When people call Susan Brower, Minnesota’s state demographer, with questions about marriage, they often want to know what older adults’ households look like, what their economic situation might be and whether they’re on their first, second or third marriage.

“All of these things have real consequences when you’re thinking about how people set up their households, how they share income, how they care for each other,” Brower said. “These are going to be really important questions in coming years as we move into the aging of the population.”

The Census Bureau wants to drop the questions on marital history because they are not required by law and are not used for county-level, tract-level or metropolitan-area analysis. As Ruggles points out, they were never meant for local analysis because the sample is too small. “These questions aren’t designed to do that,” he said.

Two other questions are proposed for elimination. One asks whether a business or medical office is located at the property where the respondent lives, and one asks what bachelor’s degree the respondent has earned. Demographers argue the bachelor’s degree question is important, too, since it is used to study the characteristics of the workforce.

The comment period for the proposed changes to the American Community Survey ends on Dec. 30.

“The Census Bureau is in a tough spot,” Brower said. “But overall my sentiment is that every single question on this survey is very important.”