“It’s an imperfect science, indeed. Under the gambit, budget forecasters estimate how much a policy change might boost the economy and send more cash flowing to the federal government. This time, Democrats are pinning their revenue hopes on the idea that major investments in the social safety net, climate policy and tax reform will yield robust, long-term economic growth.
“I’m very concerned that the pay-fors aren’t real,” said Sen. Rand Paul (R-Ky.), a fiscal conservative. “Both parties bear some culpability. But I’m worried about adding so much debt in such a short period of time.”
Both Democrats and Republicans have previously relied on dynamic scoring and both have lampooned its use as a budget trick. Predictions about how much revenue a new government policy will generate are often exaggerated or inaccurate and are difficult to calculate, placing enormous pressure on independent budget analysts to come up with favorable numbers that might turn out to be a bust.”
https://www.politico.com/news/2021/07/23/democrats-budget-hypocrisy-gop-500613