All was not lost, as demographers could still rely on surveys asking people about their marital histories as part of a separate poll, the Survey of Income and Program Participation. These are useful data as far as they go — and indeed, we relied heavily on them in a recent analysis of national divorce trends here at The Upshot. However, these marital histories are taken every five years, they’re only as reliable as people’s memories, and the results are released only years later. As such, the most recent year we have data for is 2008.

Moreover, the sample size is so small that it is impossible to track trends by state. For instance, the latest iteration includes only 23 New Yorkers who got divorced in the most recent three years. This is particularly problematic because most family policies are implemented at the state level, and so the survey can’t be used to track, say, the implications of New York having adopted no-fault divorce laws in 2010.

It gets worse. The Bush administration decided to kill that remaining family survey. Even though it later reversed itself in the face of widespread criticism, it did so with a much reduced budget, which has necessitated a host of changes in how the survey is conducted. It remains unclear just how comparable these new data will be with earlier survey rounds.

It is this emerging statistical void that makes the debate about whether the Census Bureau should continue to collect marriage and divorce information so critical. It’s also an issue ripe for confusion, because dozens of government surveys ask people about their current marital status. But current marital status is not the relevant statistic for most policy debates. For instance, it would be a mistake to infer from Zsa Zsa Gabor’s current marital status (still married) that her children enjoyed a stable family life (he’s husband No. 9). It is far more relevant to track the flow of new marriages and divorces each year, and this is the unique contribution of the questions that are to be cut from the American Community Survey. If the cuts proceed, then the United States will be the only developed country lacking annual estimates of the rates of new marriage and divorce for each age group.

There’s a bigger issue here, too. The federal government has dozens of statistical bureaus spread across countless government agencies. The result is fragmented expertise, and incentives to make decisions that reflect narrow departmental interests rather than a broader sense of the public interest. Many other countries have consolidated the various statistical groups into a coherent national statistical agency.

When I asked Jim Treat, the Census Bureau division chief in charge of the American Community Survey, whether his proposal meant that it would be impossible to measure the divorce rate in 2016, he responded: “I don’t know the answer to that question.” I found this troubling, because I know that Mr. Treat’s proposal will eliminate our only measure of the national divorce rate.