A number of other large urban districts, such as Boston and Los Angeles, have introduced their own indexes for capturing schools’ needs in recent years, though often used more narrowly, said Qubilah Huddleston, an expert on equitable school funding at the think tank Education Trust. “Districts are really hamstrung in pursuing multiple goals,” said Huddleston. “These formulas are designed to improve equity. The challenge is when you don’t have enough kids in the building.” Huddleston said she also has concerns about private fundraising playing a larger part in closing budget gaps — traditionally, a symbol of funding inequities nationally. Chicago district officials have said campuses can lean on their “Friends of” groups and other fundraising to supplement budgets.