The funding overhaul under discussion by Gov. Nathan Deal's education reform panel would shortchange metro Atlanta school districts by tens of millions of dollars, according to a new analysis by a budget watchdog group.

Overall, the Georgia Budget and Policy Institute estimates, education funding in the state would be nearly half a billion dollars lower than it should be based on the decade’s old Quality Basic Education formula, or QBE. It has been starved by so-called “austerity” cuts since 2003. Those cuts reduced the state’s payments to school systems annually, and amount to between $466.8 million and $661.9 million during the current school year, the Institute reports.

A subcommittee of Deal's Education Reform Commission last week floated a new formula that would increase funding by $241 million. As the AJC reported, the new money would increase metro Atlanta school budgets — from $27.5 million for Gwinnett, the state's largest system, to $653,000 for tiny Decatur.

But the Institute subtracts the QBE shortfall, using the $661.9 million figure, to conclude that the proposed formula would actually "cement in" a $421 million cut. This reduced funding baseline would be the starting point for future state budgets, memorializing the austerity cuts while deleting them from the discussion.

Gwinnett comes out $28.2 million poorer in such a budget, while Decatur loses $745,604. In metro Atlanta, those two districts, and Clayton, do comparatively well, though. Atlanta Public Schools is the biggest loser proportionately, with its state allocation under the proposal coming in 6.1 percent smaller than under a fully-funded QBE formula.

The funding subcommittee meets again Nov. 12 and could forward the recommendation to the full commission for its Nov. 19 meeting. The commission must send recommendations to Deal in December.