It seems like a basic concept: count every person living in America once and only once. If only it were that easy.
"We all really move around so much," said Minnesota State Demographer Susan Brower. "That's the issue here."
The next census is two years away. But work happening now by Brower, civic groups, businesses, local government employees and others stands to have a big bearing on how the population count goes in Minnesota. Preparations are ramping up because the state has a lot riding on the federal headcount's accuracy.
There are plenty of considerations feeding the Minnesota efforts to get moving, from a census budget some see as too tight, to a move to make more of the count digital, to concerns about how the data might be used.
"When census time comes around people will be missed either because they are difficult to find, they have some unusual or mobile housing situations," Brower said. "But also, there are groups of people who are hard to count because they don't want to be counted necessarily, so people who maybe who don't trust the government."
The census determines how many members of Congress represent each state. Because of population changes, Minnesota is on the cusp of losing a House seat. And federal money coming to states is often tied to population. Each person can mean as much as $1,500 gained or lost per year just in the largest 16 federal assistance programs.
That's why Brower and others across Minnesota have made the 2020 census a priority even though it is a federal initiative.
This month, Brower embarks on something of a census tour across Minnesota. It starts in Rochester and by April will take her to nine cities, including Fergus Falls, Mankato and Mountain Iron.
Along the way, she'll hold workshops to enlist local leaders in promoting the census and provide them tips on reaching hard-to-count residents. She'll urge them to set up complete count committees.
Marcia Avner is doing similar work for the Minnesota Council on Foundations.
"The only way Minnesota is going to get a good count is if we have an excited, enthusiastic, very well organized on-the-ground operation," Avner said.
Avner said philanthropic organizations feel compelled to step up because they fear the federal government hasn't devoted enough money to census operations. The Census Bureau is planning to open regional offices in Duluth, Rochester and the Twin Cities.
"That leaves two-thirds of our land mass, if you will, under-served," Avner said.
Nonprofit leaders also worry some people might be reluctant to supply the federal government with personal information, especially immigrants, given the current political climate and concerns the data they supply could somehow be used against them. Federal law requires individual information be kept confidential and bars use for things other than statistical purposes
"We think the way to get people to respond to the census is going to require that we have messengers who are in and of the community who are able to reach out to people and make the case for why this matters," Avner said.
The business community is also taking census planning seriously. A roundtable last month drew more than 30 people from the private sector to discuss the job ahead.
Joan Naymark is director of MACS 2020, short for Minnesotans for the American Community Survey.
Naymark, a former Target Corp. executive, said reliable information is key for retailers when deciding where to put stores and what to stock on shelves. They're not alone, she said.
"General contractors, retailers, the restaurant association, home builders -- you name it, everyone uses this information in some way or another," Naymark said. "To identify their customers, where the country is going economically and in communities how people live, how they spend their time, how they move around."
From his cubicle on the 18th floor of the Hennepin County Government Center, Alex Blenkush expects to be busy with census duties this year. He's a geographic information systems analyst for the county.
He'll be among staffers checking whether a vital Census Bureau database is up to date. If new homes went up in an old farm field or a commercial building was converted into rental housing, the bureau needs to know that.
That work starts in February when census officials hand over data on hundreds of thousands of properties in the county. Similar data drops will be done across the country, touching off a scramble to make corrections and possible appeals.
"Most people won't notice that the census is happening until April of 2020," Blenkush said. But, he added, "There's a lot behind it in terms of planning and coordination."
Correction (March 15, 2018):A previous version of this story misidentified the interviewee in the audio featured in this story.