This and That and Which

That and Which

Returning to that very difficult sentence in the essay by Mainly Macro titled “Fiscal rules and MMT”, I pick this time on problems concerning pronouns.   (Original text in Times New Roman; My comments in Arial narrow; My re-write in Helvetica.)

    "Most mainstream macroeconomists understand that assignment does not work at the Zero Lower Bound (ZLB), but a few disagree. To those that follow MMT fiscal rules that target the deficit are wrong because they think fiscal policy should do the job monetary policy is supposed to do in the consensus assignment, even outside the ZLB."

I find the first 'that' ambiguous in a worrying but rather trivial way. Does he mean "Most economists understand that this assignment...." ?  (One can 'find that something is the case', or 'find that book (as opposed to this book) to be ........'.) But there is here no question of using 'which'.

However, in the second sentence there are two 'thats', which present different problems. I was taught to avoid repetition, which seems a rather stupidly mechanical grammatical rule. However, we could very easily write "To those who follow modern monetary theory....", thus avoiding the repetition without damaging the sentence; indeed, improving it. The second 'that' ––  "fiscal rules that target the deficit" –––  should that 'that' be 'which'?  No! 'That' defines, 'which' describes. 

He also has a missing comma:- "To those who follow modern monetary theory, fiscal rules that...".

(However, I still do not know what on earth he is trying to say.)