I know for a fact that it’s mandatory for people who reside in the US (citizens, visa holders or those with a green card) but does that also mean foreign visitors (like those from Mexico, Canada or EU) have to complete the census too when they are on US soil? Have you visited the US during a time a nationwide census was taking place as a foreigner (alien)? If so, do you have to answer the questions present on the census even though you do not live there?


Nope. And furthermore, you’re not eligible.
You have it right, though, if you reside here then you would.
I’ve heard that in Australia it’s mandatory for non citizens to complete a census, like why?
So the government has a rough idea of how many non citizens are in Australia, and roughly where. So any services that non-citizens may need (tourism centres, consulates, etc) get put in the right place.
Because knowing where temporary residents and permanent residents are also helps with government planning not just people who are citizens.
No idea. I’m from the US. I use quokk.au because it’s super fast and doesn’t bother me with repeatedly verifying that I’m not a bot… unlike practically every other instance I’ve tried.
I googled it. Australia’s Census is based on physical presence, not citizenship or residency.
To hazard a guess (don’t know for sure, not even for my own country), it’s for future historians to be able to build up a picture of who was where and when.
What might seem obvious and common knowledge now might not be in 100 years.
Much shorter term, the point of the census is to know where people are and what they need, so government spending can be done effectively. No point building hospitals/centrelink/etc in areas that don’t need them.
Australian census records are (opt-in) deanonymised after 100 years, so there is some historical value.