I worked for the Census in 2010. I was one of the people that had to go door to door to acquire the information and forms from the folks who either didn’t fill out the questionnaire at all (for whatever reason) or didn’t fill it out completely enough (the most important info really was the number of people, and their names and ages, so that there would not be redundancy, like if someone had the same name, but their age was different) or if somehow the questionnaire got lost in the mail, got spoiled in some way, or if the questionnaire was never received by the person who was living at that particular residence at the time of the Census. We had a lot of those that were folks in the military that were either being deployed or moving to another base at the time of the Census. There are other people that moved in or out on or around that date, that also never received their questionnaire.
Although it is required by law, for you to fill out the questionnaire (you can see Here how it is proscribed by law in the Constitution, we had to memorize this info, when irate people asked us how we had the “right” to be on their property and demand this information) it is almost 99.9% unlikely that you would be arrested or fined for not filling it out.
What will happen, though, as in the case with my particular job as an enumerator is that we were required to go to the residence 5 times (at different times or days of the week) to try to get the information. If we failed on the 5th try, we would turn in the blank questionnaire (they gave us newly printed Q’s for every person in our area for whom they did not have a completed Q) and they would send out another person, and so on and so forth until they got at least part of the information (the most important being the number of resident’s, their names and ages).
This meant for the folks that didn’t fill out the form, they could have Census workers, continue to come to their home, multiple times. Some of the worst ones were when the folks knew for a fact that they had filled out the form, then the Census workers, acquired a new form with the info, but somehow their was a snafu and the new form never was accounted for, so they sent out more census workers, over and over and over, to the same address. That really pissed off a lot of people. I was in the middle, as having to be required to go out and get the info and explain to people why it wasn’t a smooth operation, and then going back to our supervisor’s and trying to explain to them how their system was effed up.
Unfortunately, they did not let us enumerators give any suggestions, after the fact, after the whole thing was wrapped up, even though we all had a lot of ideas for how we could have avoided some of the problems, inconvenience and anger, so that the next time around they could do things better.
Over all my experience with the Census was very positive. Most people were very nice, and once we explained that they were not being interrogated, that just some how their forms were never received (and that is was necessary under the Constitution) and what they do with the info (build hospitals, nursing homes, schools, employ translators, etc. where there is a need) most people were OK with it. The best folks I met, were senior citizens, who were very happy to invite me into their homes, just to chit chat. The worst people, were white men in their 60’s who had some sort of right wing vendetta against the government. One guy even called the cops on me, saying that I was trespassing on his property. Guess what, once you take an oath to work for the Census, you are not only allowed, but obligated, to go onto anyone’s property, as long as you aren’t vandalizing anything, to knock on their door and attempt to get the forms filled out accurately. So when the cops showed up, I just pulled out my little laminated card that stated that the police shall not interfere with the collecting of census data (which is also another law that most people are not aware of).
So your best bet is to give only the amount of information that you are comfortable with giving, and state your reasons for why you won’t answer the rest. If you do that, what they do, is write in a note for each Q that you “refuse” to answer and write in the reason that you “refused” usually that will take care of it, and they won’t bug you again.
Hope that helps : )