The most expensive court cases aren't over clearly written contracts that have a clause for the dispute, they're over ambiguous ones. Contracts are written to minimize costs already, and that's why they're long. Legal cases are often much more expensive for the parties than they are for the US (you could have a dozen lawyers on each side plus staff, and one judge). The existing incentives favor minimizing the amount of time spend in a courtroom.
A sign that this is working is that breach of contract doesn't show up in the supreme court very often. The big legal battles involving major corporations are usually regulatory, copyright or patent disputes wherein the parties were opposed even before the thing the case is about happened.
>Contracts are written to minimize costs already, and that's why they're long.
See OP. There seems to be this thing called "legalese" that makes contracts harder to understand than necessary.
In any case, if litigation risk is a major cost of a contract, then people drafting contracts will incorporate that factor alongside character length.
Overall, I think you may have a point. So my updated take is: Make the per-character tax low enough that it's not a factor for B2B contracts where it's standard for lawyers on both sides to review. However, make it high enough so that it's a factor in rental contracts, employment contracts, and EULAs, where at least one party typically doesn't retain a lawyer.
Legalese is a cost-reduction technique founded on the principle of making your potential future case look as much like a previous case, even word for word, as possible.
Legalese features complex grammar, anyone with good English skills and a lot of time could rewrite most laws so they are much easier to understand without losing all the cost reduction legalese provides.
A sign that this is working is that breach of contract doesn't show up in the supreme court very often. The big legal battles involving major corporations are usually regulatory, copyright or patent disputes wherein the parties were opposed even before the thing the case is about happened.