[burroisolator]

I feel like the quote you pulled out of Youtube is slightly unfair in the extent to which he endorses the idea. In my opinion, it sounds like he full-throat endorses the general method and aim of the idea just not the exact transfer amounts and the method to raise revenue (sales/VAT tax vs carbon tax). Here is the quote in more context:

"The plan is just a version of the negative income tax. Milton Freedom first proposed it...and as a student 40 years ago I thought it was a pretty good idea. And it turns out I wasn't alone in that judgement...In 1968 a 1000 economists endorsed a negative income tax along these lines. What Andrew Yang is proposing is a version of what these 1000 economists endorsed back in 1968. Could 1000 economists all be wrong? Laughs Well yes they could. But I don't think in this case they are. My own view is that a universal income financed by an efficient tax, something like a value added tax, might well be worth considering. And I'm one of the signatories...of a plan to do something similar with a carbon tax."

[gnicholas]

I don't hear the words you hear. At the end, he says "of a plan to do something in a smaller way with a carbon tax"

As in, the $1k/month thing is too big, and he thinks we should consider doing something smaller. How much smaller? We don't know for sure, but I doubt economists would support a carbon tax that would approach the level of $1,000/mo for every adult in the US. The primary purpose is to internalize the externalities of pollution, not to generate revenue.

The fact that an economist thinks a concept is worth considering is a far cry from saying they are endorsing a specific instance of one of those things. It's one thing to say he endorsed the concept. It's another thing to say he endorsed the plan. He didn't.