After lengthy hearings held over several months, a legislative study commission has recommended more study.

Surprise, surprise. What is most dismaying is that the study’s subject, tax breaks that riddle the Louisiana tax code, is a particularly pressing subject because the state can use every dollar it can get these days.

The lawmakers on the Revenue Study Commission did provide a list of tax exemptions and credits that might, maybe, perhaps or could be reduced or eliminated.

Or studied.

The commission’s report is “plenty of nothing,” wrote conservative blogger Jeff Sadow, and his comment is hardly a great exaggeration. It is difficult to see how many tax breaks can be curtailed if a year’s work doesn’t come up with even a few sacrificial lambs.

“As Louisiana contemplates a fifth consecutive year of cuts to health care, education and other critical services, the need to reform the tax-exemption process has never been greater,” said the liberal Louisiana Budget Project.

At best, as the Public Affairs Research Council commented, the study raised awareness of just how many such exemptions breaks are allowed in law, and how difficult it is to get the information to evaluate whether a break is achieving whatever purpose the Legislature had in enacting it.

Since some breaks go back many years or even decades, it seems at least a no-brainer to set a drop-dead date for a break. If it is found to be a poor investment of tax dollars, the break would “sunset,” or if it is found to be valuable, it could be renewed.

These are “tax expenditures,” because the effect is the same as the state writing the favored industry or trade group a check from the taxpayer.

The commission’s report did not even bother to suggest guidance to Gov. Bobby Jindal, who says he wants to eliminate tax breaks as part of a wider tax code rewrite.

As the commission’s report noted, it’s difficult to get information that backs up the effectiveness of breaks. The Department of Economic Development is still working on some detailed reports on its incentives sought by the commission.

Another point for future study: “Where appropriate and feasible,” the commission report said, “an annual cap on the amount of state revenue foregone for a particular tax expenditure could allow for more budget certainty.”

That sounds good, but a tax exemption might be very difficult to cap in that way. The administrative burdens might typically be too great.

However, there is little debate that the state is missing out on revenues because some powerful interests get legislators to cut them a “tax expenditure” check. Unhappily, the Revenue Study Commission hasn’t plugged any leaks.