Not so easy.
But yeah I get it. Obviously the basic economic assumptions ignore:
1) government in general, but especially tax law. It's WAY too complex to model, unfortunately (and I doubt that's a coincidence), nor is it even constant.
2) it ignores that the vast majority of markets are supply- or demand- constricted. In reality demand graphs flatten off at some point. Let's take bread. There is only demand for so much bread, and lowering the prices past a point no longer increases demand at all. So you can see it exists.
Supply bound is similar. We are just not going to produce more land than there is. That market is absolutely supply bound.
The weird thing economics glosses over is that nearly every market is either supply constricted or demand constricted, and the common equations just don't work there.
3) information. Economics assumes perfect information, when that obviously doesn't exist. Information spreads though, so over very long time frames perhaps there's a case to be made that perfect information does exist as long as the information is old enough.
The thing is, whilst I might agree that the first one is at least theoretically solvable, it's just too much work. The second and third are impossible to model. And I bet you could come up with 10 more.
Example of a subfield addressing your 3): https://en.m.wikipedia.org/wiki/Information_economics
I believe 2) is addressed as well but I am not a professional economist so maybe someone can help edify us.
A similar problem exists for 2. Yes I can find a paper or two, or probably even more that talk about it, but they don't exactly have a wide following because it just makes things too hard.
Incorporating both ? Can't even find a paper on it.
- Here is a set of assumptions which are obviously wrong
- Given that set of assumptions, we can make this model, which has been shown not to hold true in reality due to the above
- Repeat ad nauseum