The federal government's energy numbers crunchers are close to finishing a study that would provide some clarity on whether ending a 39-year-old ban on exporting crude oil would affect gasoline prices.

The U.S. Energy Information Administration study won't directly answer how crude exports would move gasoline prices, agency chief Adam Sieminski told reporters Monday at EIA's Washington headquarters. Officially, it will evaluate how responsive gasoline prices are to fluctuations in U.S. and international energy price indices — but could provide insight as to whether exports would exacerbate market price trends, Sieminski noted.

The evaluation could clear up questions about how closely domestic prices are tied to world markets, Sieminski said. Export opponents have said that shipping crude abroad would raise domestic prices, while boosters say it would clear regional supply gluts, generate revenue and incentivize new drilling to stabilize costs.

The study is due in September, and comes partly because of congressional interest in crude exports, Sieminski said. The U.S. permits only a trickle of crude oil exports, and some lawmakers have pushed the Obama administration to relax the restrictions.

Export advocates argue that U.S. refineries aren't equipped to process the light, sweet type of crude being coaxed out of tight-rock formations through hydraulic fracturing, or fracking.

The EIA also intends to look at that refinery "mismatch," as it has been referred to in the growing debate about crude exports.

A separate study, also due in September, would look at the costs for upgrading refineries to handle that light, sweet crude. It also will attempt to parse out refinery capacity by crude variety, Sieminski said.