The federal government can legislate — and regulate — but neither thing can suspend economic laws any more than passing a law forbidding gravity can make a bowling ball float weightlessly.

So when the federal government passed a law back in 2010 limiting the processing fees that banks could charge retailers when a customer pays for an item with a debit card, the banks found ways to recoup the lost revenue. That’s about as surprising as discovering that a bowling ball dropped out of a window will fall to the ground below.