Suppose BHO Insurance Co. decides it wants to corner its state's market in automobile coverage. It begins an aggressive ad campaign offering a too-good-to-be-true deal: Sign up with us, and we'll give you better coverage at lower premiums. We're so sure you'll love our deal that if you like the terms of your existing policy, you'll be able to keep them--GUARANTEED! The ad campaign, with the company's charismatic president acting as pitchman, is a smashing success. The competing companies lose so much business that they declare bankruptcy or are acquired by BHO. But BHO's policies are more expensive, and they...