I have devoted myself to studying the economic organization of industries for thirty years. It has been my good fortune to work at places that tol- ated my gadfly approach to research. So long as I produced a few publi- tions each year and wooed a few graduate students to share those interests, I was free to sample a smorgasbord of economic delights: why firms div- sify, the competitive role of advertising, strategies for selling in overseas markets,...