Yes, perhaps it was the Bureau of Labor Statistics. I felt sorry for the lady who regularly phoned us and had to cajole businesses into taking the time to answer. It was 20+ years ago. I remember there was no legal requirement that we answer, although they never stated that.
We also got normal Census Burau surveys by mail occasionally, perhaps every 5 or 10 years, that we WERE compelled by law to answer. Those could be quite involved.