NOT LONG AFTER President Nixon took the unprecedented step of imposing peacetime wage and price controls, the American people learned a basic economic lesson: Artificial controls don’t work unless underlying costs are controlled. Four decades later, the Patrick administration is imposing controls on small business health insurance rates. The move will prove to be little more than an election-year reprise of Nixon’s failed effort. The Commonwealth’s 2006 health care reform was supposed to help address rising health insurance costs for small businesses. It hasn’t — and small businesses are paying the price.