2018 is not a Census year.
I know.
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There is, however, a Census Test underway. That must be what you experienced.
I threw away the paperwork. I actually forget what it was, but I'll take your word for it.
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By law, you must respond to census surveys. I seriously doubt, though, that you are required to respond to census tests.
Apparently not re: census tests, as they finally gave up on me.
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One of my many weirdo jobs while attending school, was being a census taker. At the end of the summer, they were pretty much done with the household census, but they had to let us work until the end of the summer. GOVT JOB, ya know?
So, they send my friend and me to the local nuthouse.
These people were so nuts that you couldn't interview them. We had to fill in the forms from their records in the main office.
Nice tawking to you this fine AM!
If you think education is expensive, try ignorance.