Census officials discovered data issues that could delay its completion, internal documents show

Census Bureau officials discovered data issues while working through 2020 Census responses, which include several “high complexity” problems and threaten to delay completion of a key tally until February, according to a new set of internal Census documents shared by House Democrats on Wednesday.

That delay would mean the Trump administration would be unable to implement its plan to exclude undocumented immigrants when dividing seats in the US House of Representatives, as President Donald Trump leaves office on January 20. Several federal courts have blocked this policy, and on Monday the Supreme Court heard arguments over the matter.

Several of the issues are of “high complexity” and incorrect handling would skew the count smaller or larger in some areas, the documents say. The issues include the ways the Census Bureau accounts for multiple responses and responses that are not linked to a specific address.

The documents do not specify the precise extent of the largest issues. But the documents estimate an additional 20 days are needed for data processing, putting completion in late January or early February.

The Census Bureau issued a statement later Wednesday asserting that “these kinds of anomalies and issues are expected and are similar to the Census Bureau’s experience in prior decennial censuses.”

“Internal tracking documents would not convey the uncertainty around projected dates and may fail to reflect the additional resources employed to correct data anomalies,” the statement said. “The anomalies affect less than seven-tenths of one percent of records and are being resolved as expeditiously as possible.”

The bureau also said it “is working to thoroughly correct and address all issues and anomalies as a part of its mission to deliver accurate 2020 Census data products as close to the statutory deadline as possible.”

In a letter to Commerce Secretary Wilbur Ross on Wednesday, House Oversight and Reform Committee Chairwoman Carolyn Maloney said that the documents did not come from Ross despite committee requests for them last month. She threatened to subpoena him if he did not provide additional documents.

“Despite the Trump Administration’s obstruction, the Committee has now obtained several internal Census Bureau documents from another source that not only confirm these press reports, but indicate that unresolved errors may be more extensive than first reported,” Maloney wrote. “I write to urge you to end your obstruction of the Committee’s inquiry on this critical issue and produce a full and unredacted set of the documents requested by the Committee. If you refuse, the Committee will have no choice but to issue a subpoena.”

Census Bureau Director Steve Dillingham had acknowledged census issues in a November statement.

“During post-collection processing, certain processing anomalies have been discovered,” he said at the time. “These types of processing anomalies have occurred in past censuses.”

Officials did anticipate some issues, like two different responses for a single household, and had plans to address those, but Dillingham and other Census officials did not explain the nature of the problem in November.

That count was on track to be finished by “the first or second week of January,” Al Fontenot, the career official leading the 2020 census, said in late October.

But meeting that target “assumes that a reasonably smooth series of processing events will occur,” Fontenot said at the time. “If they are not reasonably smooth, that will require us to take additional time.”

This story has been updated with a statement from the Census Bureau.