Sometimes a new, undetected building is the source of such discrepancies, but often it’s an existing building being used differently. Three electric meters or four doorbells at a two-family home may be a clue that it has more than two families. If the local government canvassers can document these discrepancies, they can propose adding the address to the master list or modifying the address to reflect the presence of additional housing units.
This is important for counting the unauthorized immigrant population, particularly in a city like New York, where many newcomers live in makeshift illegal apartments, and where neither the dwellings nor the occupants will show up in any other administrative records.
Once on the list, those units are sent a census form. If there is no response, a census field worker tries to gather the information in person. If there’s still no response, the census taker works to gather information from a proxy, like a landlord or neighbor. If this fails and the census staffer believes the address is valid and occupied, a count is imputed for the household based on the characteristics of surrounding housing units for which good information was obtained.
Once an address makes it into the master address file and there is some sign of occupancy, there will be population assigned to it, whether somebody returns the form or not. The response might not be as accurate as if a resident returned the form, but it will not result in zero population, either.
In New York City, this work of finding missing addresses began back in 2016, and by the time the census was conducted for 2020, there were 122,000 additional housing units on the list of households to be counted. State officials made a similar effort on a broader scale, using administrative records to send local officials to investigate addresses and find group homes housing multiple residents. They managed to get a further 80,000 addresses added to the list.
It’s not clear exactly how this affected the census results, but it was enough to establish that New York had in fact grown over the past decade. Some clues emerged from technical data the bureau released last week with the first numbers, “Operational Quality Metrics,” which break down the general parameters of the count.
According to this data, New York’s master address list grew by 693,000 statewide, and after invalid addresses and vacant units were filtered out, the census counted population in 446,000 additional housing units compared with 2010, which could reflect both new units the census already knew about and the LUCA efforts. That’s a 6 percent increase that jibes with the 4.2 percent population growth.