widespread cheating is still a net plus though, worst case scenario they pay less taxes then needed, but any non-zero number would be money that otherwise wouldn't have been recieved. Actual calculations can be done on audits so if someone sends something in that is drastically different than what you would expect it should be then they can do the actual calculation but for the most part estimates should work fine for that matter.

The way I see it a 5 to 10% variance in what is actually owed isn't going to mean much in the long run, and if a number is submitted that does raise eyebrows, which would be easy to implement just based off what their annual income(which is already reported) is versus what their reported assets are, a more in-depth calculation can be done