In more than half of the states in the U.S., the poorest school districts do not receive funding to address their students' increased needs – just the latest data point to shine a spotlight on funding gaps that plague the country's public education system.

School districts with the highest rates of poverty receive about $1,000 less per student in state and local funding than those with the lowest rates of poverty, according to a new report released Tuesday by The Education Trust.

While the funding gaps among states vary significantly, Illinois, Missouri, New York and Alabama rank among the worst. In Illinois, for example, the poorest districts received 22 percent less in state and local funding than the lowest-poverty districts.

"FIGURE 1: Gaps in State and Local Revenues per Student Between Districts, Serving the Most and the Fewest Students in Poverty" as shown in the report titled "Funding Gaps: An Analysis of School Funding Equity Across The U.S. And Within Each State." (The Education Trust)

Schools and school districts that serve large proportions of poor students have historically been shortchanged when it comes to things like access to high-quality teachers, advanced course offerings, early education programs and school counselors – resources that are directly linked to the amount of funding available.

The silver lining, researchers point out, is that the situation seems to be improving, albeit slightly. Since 2015, when The Education Trust previously examined this funding gap, the difference in resources allocated to school districts with high poverty versus low poverty has closed by about 3 percentage points.

"As we saw in the 2015 report, there is a lot of variation in the funding gaps within states, but overall, we see a small uptick in the number of states providing more funding to their districts with higher percentages of students form low-income backgrounds," the report states.

In 20 states, the report notes, the highest-poverty districts received at least 5 percent more in state and local funds than the lowest-poverty districts. And in six states, the highest-poverty districts received at least 15 percent more funding per student than the lowest-poverty districts, including Georgia, Minnesota, New Jersey, Ohio, South Dakota and Utah.

That trend could continue given the number of states rethinking their school funding formulas in an attempt to make their education finance systems more equitable, especially for school districts that serve lots of students in need of extra supports, such as poor students, students with disabilities and those learning English.

Illinois, for example, which the report found to have the biggest funding gap, was one of the last states in the country whose education funding system relied almost entirely on property taxes, spawning a vicious and inequitable funding cycle that left property-poor districts with large numbers of low-income students chronically underfunded. That changed last summer, when state legislators approved a new funding formula that directs more resources to poor and rural districts.

Still, The Education Trust report makes clear that too many students aren't getting their fair share of funding.

"The funding gaps between high and low poverty districts look even worse when we consider that students in poverty are likely to need additional supports in order to succeed academically. In other worse, simply offering equal funding isn't enough," the report underscores.

When the researchers ran their analysis to account for these additional needs, using a federally defined assumption that it costs districts 40 percent more to educate a students in poverty than a student not in poverty, the funding gap widened substantially. When accounting for the additional needs, the report shows that highest-poverty districts receive about $2,000, or 16 percent, less per student than low-poverty districts.

"FIGURE 2: Gaps in State and Local Revenues per Student Between Districts, Serving the Most and the Fewest Students in Poverty" as shown in the report titled "Funding Gaps: An Analysis of School Funding Equity Across The U.S. And Within Each State." (The Education Trust)

The altered analysis showcases why equal funding is not the same as equitable funding – a theme coursing through so many education debates today.

The researchers were also quick to point out that even among high-poverty school districts that do receive more funding per student from their state, that doesn't always mean the schools in those districts are funded equitably. As past research shows, even when states use funding models that weight poverty more heavily, districts often don't follow suit.

The report also looked a funding disparities between districts serving the most students of color and those serving the least, finding an even larger funding disparity than that of poverty levels. On average, districts serving the most students of color received about $1,800 per student, or 16 percent.