One of the most tired, predictable tropes in policy analysis is that both sides are wrong. But sometimes, both sides really are wrong. And medical malpractice may be a case in point.

Conservatives tend say malpractice is a major factor in rising health care costs, in part because doctors and hospitals end up practicing so much defensive medicine. Liberals typically counter that the estimates of defensive medicine, and malpractice costs generally, are wildly overblown.

A new paper in Health Affairs, just released this morning, suggests the truth is somewhere in between. Amitabh Chandra, one of the co-authors, explains:

Physician and insurer groups like to collapse all conversations about cost growth in health care to malpractice reform, while their opponents trivialize the role of defensive medicine,. Our study demonstrates that both these simplifications are wrong—the amount of defensive medicine is not trivial, but it’s unlikely to be a source of significant savings.

The Affordable Care Act, by the way, includes some pilot programs to test alternative systems for settling malpractice cases. They don't have enough money behind them, but they are a step in the right direction.