The study assumes that none of the money collected will be spent on other programs, so this tax, like ANY tax will have a contractionary effect.
It’s only a few paragraphs down that they mention this.
It’s called burying the lede:
Senator Elizabeth Warren’s proposed wealth tax would slow the United States economy, reducing growth by nearly 0.2 percentage points a year over the course of a decade, an outside analysis of the plan estimates.
The preliminary projection from the Penn Wharton Budget Model, which was unveiled on Thursday in Philadelphia, is the first attempt by an independent budget group to forecast the economic effects of the tax that has become a centerpiece of Ms. Warren’s campaign for the Democratic presidential nomination.
The assessment found that if the tax raised as much new federal revenue as Ms. Warren intends, and if the proceeds went toward reducing the federal debt, annual economic growth would slow from an average of 1.5 percent to an average of just over 1.3 percent over a decade.
The model did not assess growth effects from Ms. Warren’s spending plans, which critics said undercut its findings. Economists who favor Ms. Warren’s plan said the analysis did not accurately account for the economic boost from programs she would fund with the tax revenue, including universal child care, increased education funding and student loan forgiveness.
Instead, it assumed that the tax revenue would be used to reduce the national debt, a move that encourages growth in the Penn Wharton simulation. Had the Penn Wharton model factored in the money’s going into programs rather than paying down debt, it most likely would have produced an even larger drag on growth from the wealth tax.
So, their model calls upon the austerity fairy in order to make their numbers.
This analysis is complete bullsh%$, and the report is even more cow excrement.