After a monthslong investigation into federal education funding, U.S. News concluded that much of the $14.5 billion meant to provide poor children with an education comparable to rich children's is in fact flowing to school districts with lower-than-average poverty rates.

The why has to do with a complicated formula based on sometimes outdated data that inflates money going to school districts in small states, large school districts and localities that can devote more money to K-12 education. Read more in our investigation: Rich School Districts Get Millions in Federal Money Meant for Poor Kids.

In education policy circles, the formula's shortcomings are common knowledge, and have been the subject of much discussion.

The Alliance for Excellent Education has explored how to better address the needs of high school students with Title I (funds are often prioritized for elementary or middle school instead). The Brookings Institution has looked at how funds are spent, saying simply that the program "doesn't work."

Some have also proposed new formulas. The Center of American Progress has run analyses of a formula it says "is much better than the current formulas at targeting Title I dollars to settings of concentrations of poverty." An analysis from Nora Gordon published by The Hamilton Project called for Congress to remove state-level spending per pupil from the formula, to eliminate two of the four sub-formulas used to calculate a school's funding, and to raise the minimum requirement to receive funds from a 2 percent poverty rate (or 10 poor children) to a 5 percent poverty rate. Gordon, an associate professor at the McCourt School of Public Policy at Georgetown University, has provided her data to U.S. News.

Despite the clear problems with the formula and the available options for change, Congress has dragged its feet on an overhaul. This won't come as a surprise given recent criticisms of the "do-nothing" Congress that suffered from low productivity rates and low approval ratings . But the problem actually spans decades.

While the fight for formula change has founds some advocates, they've found it impossible to convince their colleagues to enact even miniscule changes.

These advocates saw an opening while No Child Left Behind was being rewritten last year.

Sen. Richard Burr, R-N.C., put forth a proposal that would have, among other things, barred districts with extremely low poverty rates from receiving Title I money, eliminated the reward given to states that spend more on education, and based the formula in part on national per-pupil expenditures. It was slashed.

In the House, one of the most ardent advocates for changing the formula, Rep. Glenn Thompson, worked for change as well. A Republican from Pennsylvania, Thompson represents a sprawling northwestern swatch of the state that covers the Allegheny National Forest, small rural communities and once-thriving mid-size factory cities where per capita income hovers around $20,000, according to the U.S. Census.

After years of watching Congress block legislation to overhaul the formula, he decided this time to adjust his expectations. He persuaded his colleagues to include a slight tweak to the formula that would have weighted the concentration of poverty by one one-hundredth of a percent more than it currently does -- a change that would likely only amount to a few hundred dollars difference per district. But even that change never made it into the final version of the bill signed into law last December.

Under Burr's overhaul, 36 states would have gained money. But those that stood to lose funding, in some cases, would have lost big. New York would have waved goodbye to more than $300 million, Pennsylvania nearly $130 million and Illinois $180 million.

On the district level, 3,000 districts would have gained money while more than 10,000 would have lost money. One of the main complaints of the law now is that the money is spread too thin and that in many cases it goes to rich districts with robust local revenue that don't need the federal funds to support their poorest children. His overhaul seeks to target the money to the poorest districts.

The largest monetary gains would have gone to the Los Angeles Unified School District in California, the Houston Independent School District in Texas and the Dallas Independent School District in Texas. All would have nearly doubled their current Title I allocations.

While the numbers of poor students in city school districts are significant, the concentrations of poverty in cities often aren't, a result of the sometimes large number of upper-income individuals moving back into urban areas. That's not to say those urban districts don't have poor students. On the contrary, they're home to some of the most extreme pockets of poverty in the country.

But because of the new focus on concentration of poverty as opposed to the number of children in poverty in Burr's formula, large school districts -- some of which are already struggling with debt -- would lose a lot. Chicago Public Schools in Illinois, and the New York districts of Kings County, Bronx County and Queens County would have experienced the largest monetary losses.

Herein lies the issue with formula change. Even if legislators agree that a formula would be more fair to the law's original purpose of equalizing education funding across incomes, the actual changes are more difficult for them to agree on. With each proposal, some districts win and some districts lose. Any potential change to the formula would likely require some officials in Congress to vote in favor of their constituents receiving less money.

Case in point: Upon getting wind of the proposal, Sen. Richard Durbin, the powerful Democrat from Illinois, charged to the chamber floor in opposition.

"That's a 21 percent reduction to help poor and low-income students," he said in opposition to Burr's proposal. "Chicago Public Schools alone would lose $68 million. I don't know what procedural tools are available to us, but I will use every tool in the box to stop this."

Chicago is a whopping $1.1 billion in debt; Detroit's schools are $515 million in debt. Philadelphia is backing a lawsuit against the state over unequal funding, citing its inability to maintain facilities and employ teachers and nurses.

To avoid those drastic changes, some policymakers have proposed a stepped solution that would slowly fix the formula with small changes to districts each year.

Thompson's proposal put this theory to the test, though his minor tweak to the weights would have changed each state's funding by less than a percentage point.

The largest loss of funds would have been in Florida, which would have lost $5 million of of its $735 million grant -- a decrease of just 0.69 percent.