Ex Ante and Ex Post: What Does Rod Stewart Really Know Now?1

Do we really know whether or not we have “maximized” utility, or do we just know that we are “happy” or “sad”? We argue that we can never know objectively whether or not utility has been maximized; however, people acting on a free market are sufficiently close to the decision as to be able to hazard a better guess about their opportunity costs than policy makers.