Scholes 1 considered the effect of secondary sales of large blocks of stock on the price of the stock. However, he only looked at price changes occurring just before and just after the sale took place. It is argued here, using a simple model, that if traders have rational expectations they may anticipate the sale, and prices could reflect this possibility long before it actually occurs. To determine the full effect, it may therefore be necessary to consider the price path many months, or even years, before the sale.

Scholes [1] considered the effect of secondary sales of large blocks of stock on the price of the stock. However, he only looked at price changes occurring just before and just after the sale took place. It is argued here, using a simple model, that if traders have rational expectations they may anticipate the sale, and prices could reflect this possibility long before it actually occurs. To determine the full effect, it may therefore be necessary to consider the price path many months, or even years, before the sale.

We argue that many goods and decisions are not allocated or made through markets. We interpret an agent's status as a ranking device that determines how well he or she fares in the nonmarket sector. The existence of a nonmarket sector can endogenously generate a concern for relative position in, for example, the income distribution so that higher income implies higher status. Moreover, it can naturally yield multiple equilibria. It is thus possible to explain differences in growth rates across countries without recourse to differences in underlying preferences, technologies, or endowments. Different social organizations lead to different reduced-form preferences, which lead to different growth rates.

A standard demand-deposit contract in which individuals are entitled to their full deposit at any time provided the bank is solvent is analyzed in a context in which there are no exogenous events on which agents condition their behavior and a unique equilibrium involving a bank run with positive probability is shown to exist.

We study transactions that require investments before trading in a competitive market, when forward contracts fixing the transaction price are absent. We show that, despite the market being perfectly competitive and subject to arbitrarily little uncertainty, the inability to jointly determine investment levels and prices may make it impossible for buyers and sellers to predict the prices at which they will trade, leading to inefficient levels of investment and trade.

We examine an economy in which the cost of consuming some goods can be reduced by making commitments that reduce flexibility. We show that such consumption commitments can induce consumers with risk-neutral underlying utility functions to be risk averse over small variations in income, but sometimes to seek risk over large variations. As a result, optimal employment contracts will smooth wages conditional on being employed, but may incorporate a possibility of unemployment.

People may be surprised to notice certain regularities that hold in existing knowledge they have had for some time. That is, they may learn without getting new factual information. We argue that this can be partly explained by computational complexity. We show that, given a knowledge base, finding a small set of variables that obtain a certain value of R 2 is computationally hard, in the sense that this term is used in computer science. We discuss some of the implications of this result and of fact-free learning in general.