Starting next week and continuing into October, you might see people carrying laptops walking through your neighborhood and knocking on doors. They’re what the Census Bureau calls “listers” — census workers charged with making sure the bureau has a complete list of all addresses as it prepares for its massive population count next year. It’s the first major field operation of the 2020 Census. Starting next Monday, Aug. 19, listers will begin verifying the remaining 35% of addresses that need double-checking, using maps and a list of known addresses on a laptop. Mostly, they will be checking to see whether...