IRS officials are trying to figure out what data the agency can collect on new incentives created under the 2017 tax overhaul, but the best hope for revealing whether the tax breaks are aiding low-income areas-rather than accelerating gentrification to the benefit of the wealthy-likely rests with Congress.

The Senate’s version of the tax law originally included a fairly open-ended requirement for the Treasury Department to track and report to Congress the progress and impact of the tax breaks, including poverty reduction and job creation. The opportunity zone reporting requirements are mentioned in the conference committee’s statement accompanying its report on the tax overhaul, but the language was removed from the Senate’s version of the bill before passage.

Former acting IRS commissioner Steven Miller, now national tax director at Alliant group LP, said the agency should have the general authority to request information that would justify funds’ getting the tax breaks-but little beyond that, and almost certainly not information on how the funds reshape the communities in which they invest.

Madrigal said Treasury could model opportunity zone reporting requirements after the requirements for the New Markets Tax Credit, which Treasury doles out to applicants seeking to invest in low-income communities. Sen. Cory Booker, one of the two authors of the original opportunity zones legislation, is working on a bill that would require the Treasury Department to report to Congress on the effects of the tax breaks, according to a Senate staffer.

The original version of the tax overhaul brought to the Senate floor included a requirement that the Treasury Department submit an annual report of how many tracts received opportunity fund investments, the funds’ asset classes, and poverty reduction and job creation as a result of the funds’ underlying businesses.