EconAir

It is a puzzlement why the stock market can go up while the economy is in a virus-caused depression. Much of the economy is in lockdown or closed because of decreased consumer demand. As many of one-third of workers and many small businesses are on federal life-support programs. Profits have disappeared. Large numbers of bankruptcies loom. Given the uncertainty, including recent record numbers of new virus cases, the usual stock evaluation metrics are worthless. With the economy tanking, how come the stock market has gone up dramatically? And continues to go up. THE STOCK MARKET Let’s decompose the stock market. When people talk about the stock market going up or down, they usually refer to an index such as the S&P 500 as the measurement. The S&P 500 is a market-value (cap, short for capitalization) weighted index. The ten most valuable companies account for over 20% of the total value of the index. There are over 3,000 actively traded stocks. But the 500 comp

DEFINITION OF A BILATERAL OLIGOPOLY Models of market structure assume that the demand side is represented by a large number of buyers.  The structure of the market, and the assumed market outcomes, depends on the number of suppliers and how they compete.  Suppliers either post one price or exploit their knowledge of buyer categories by using price discrimination.  Despite the comments about the key role of consumers in determining economic performance, consumers are fairly passive when the discussion focuses on imperfectly-competitive industries.  But many markets are not structured this way; the buyers are not passive consumers but large corporations that do not passively accept suppliers’ prices.  Net prices are actively negotiated.  These markets are often bilateral oligopolies. In a bilateral oligopoly the buyers are not an undifferentiated mass of consumers but rather a small number of purchasing agents or professional buyers representing large purchasers.   T