Introduction, 410. — Single-period versus multiperiod decision making, 411. — Simultaneous choice in a multiperiod process, 413. — Alternating choice in a multiperiod process, 416. — The method of backward induction, 417.— General quadratic profit functions, 420. — Reduced quadratic profit functions, 422. — Asymptotic results, 425. — The cost of competition and the benefits of trust, 427. — Conclusion, 428.