A panel discussion this week offered the first preview of the legislative battle over Louisiana’s generous — and unaffordable — program of subsidies to the film industry.

Everyone, even the industry’s leading booster, agreed that reform is needed in a program that has grown more than 500 percent in a decade. The subsidies are the most generous in the land, and they have helped Louisiana displace Hollywood as America’s filmmaking capital. But to cover the cost of the film subsidies and other costly giveaways, Louisiana has cut higher education spending in half, forcing colleges to increase tuition and burying students in debt.

Panelists discussed a variety of ways to tinker with the formula to boost local low-budget films and curtail state subsidies for big-dollar stars who wind up spending Louisiana’s tax dollars in Hollywood.

But we’ve been tinkering with the formula for a decade, and every time we’re assured that the program’s costs have been brought under control.

That hasn’t happened, so any real reform must include a cap on the costs of the subsidies.

The film industry opposes that idea, saying a spending cap will cause filmmaking to be concentrated in the first part of the year, and business will dry up when the subsidies are used up.

Legislators should reject that argument, set a cap and then design a formula that crimps the subsidies in a way that the money will last the whole year. The industry can be a constructive partner in that process but not if it gets greedy and fights the interests of the taxpayers of Louisiana.