Calculate the hidden cost. Tell the companies that you'll either vote for a tax or accept a lucrative post in their board of directors after your term is over. Profit!
Calculate the hidden cost. Spend half of the cost on a marketing campaign to sway public opinion against a tax. Profit!
Maybe one way to mitigate is to have a separate branch of the political system dedicated to calculating the costs. Then make the methods for calculating as publicly available as possible so that they can be reproduced by non-profits.
We have managed judicial systems. We can manage this too.
I don't see how that helps. For example there are many publications available that calculate the cost of CO2, eg [1] from the German government. Yet global warming is still a problem.
Calculate the hidden cost. Spend half of the cost on a marketing campaign to sway public opinion against a tax. Profit!