As mentioned in a previous post , Israel Kirzner distinguishes between Type A and Type B knowledge problems. To quote that post: Type A problems involve undue optimism, and are self-correcting: if I think I can sell my programming services for $1 million per hour, I surely will be disappointed, and, if wise, I will lower my price. My very attempt to act on my over-optimistic beliefs reveals their falsity. Type B problems, on the other hand, involve undue pessimism, and are not self-correcting. I may believe that my current boss, who is paying me $50 per hour, is the best employer I can find. But, unbeknownst to me, just down the block is someone who would happily pay me $100 per hour, if he knew of my existence . And I would happily go work for him, if I knew of his . For type B problems to be "corrected" requires entrepreneurial action, perhaps, say, a job placement firm that will alert both the potential new employer and me to each other's presence in the ma