Yakov Amihud

Illiquidity and Stock Returns: Cross-Section and Time-Series Effects

This paper shows that over time, expected market illiquidity positively affects ex ante stock excess return, suggesting that expected stock excess return partly represents an illiquidity premium. This complements the cross-sectional positive return–illiquidity relationship. Also, stock returns are negatively related over time to contemporaneous unexpected illiquidity. The illiquidity measure here is the average across stocks of the daily ratio of absolute stock return to dollar volume, which is easily obtained from daily stock data for long time series in most stock markets. Illiquidity affects more strongly small firm stocks, thus explaining time series variations in their premiums over time. r 2002 Elsevier Science B.V. All rights reserved. JEL classificaion: G12

Asset pricing and the bid-ask spread☆

Abstract This paper studies the effect of the bid-ask spread on asset pricing. We analyze a model in which investors with different expected holding periods trade assets with different relative spreads. The resulting testable hypothesis is that market-observed expexted return is an increasing and concave function of the spread. We test this hypothesis, and the empirical results are consistent with the predictions of the model.

Dealership market: Market-making with inventory☆

Abstract This study considers the problem of a price-setting monopolistic market-maker in a dealership market where the stochastic demand and supply are depicted by price-dependent Poisson processes [following Garman (1976)]. The crux of the analysis is the dependence of the bid-ask prices on the market-makers stock inventory position. We derive the optimal policy and its characteristics and compare it to Garmans. The results are shown to be consistent with some conjectures and observed phenomena, like the existence of a ‘preferred’ inventory position and the downward monotonicity of the bid-ask prices. For linear demand and supply functions we derive the behavior of the bid-ask spread and show that the transaction-to-transaction price behavior is intertemporally dependent. However, we prove that it is impossible to make a profit on this price dependence by trading against the market-maker. Thus, in this situation, serially dependent price-changes are consistent with the market efficiency hypothesis.

Market Microstructure and Securities Values: Evidence From the Tel Aviv Stock Exchange

This paper examines the value effects of improvements in the trading mechanism. Stocks on the Tel Aviv Stock Exchange were transferred gradually from a daily call auction to a mechanism where the call auction was followed by iterated continuous trading sessions. This event was associated with a positive and permanent price appreciation. The cumulative average market-adjusted return over a period that started five days prior to the announcement and ended 30 days after the stocks started trading by the new method was approximately 5.5%. In addition, we find positive liquidity externalities (spillovers) across related stocks, and improvements in the value discovery process due to the improved trading method. Finally, there was a positive association between liquidity gains and price appreciation. Our results suggest that improvements in market microstructure are valuable.

Liquidity and Asset Prices: Financial Management Implications

Stable URL:http://links.jstor.org/sici?sici=0046-3892%28198821%2917%3A1%3C5%3ALAAPFM%3E2.0.CO%3B2-XFinancial Management is currently published by Financial Management Association International.Your use of the JSTOR archive indicates your acceptance of JSTORs Terms and Conditions of Use, available athttp://www.jstor.org/about/terms.html. JSTORs Terms and Conditions of Use provides, in part, that unless you have obtainedprior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content inthe JSTOR archive only for your personal, non-commercial use.Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained athttp://www.jstor.org/journals/fma.html.Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printedpage of such transmission.The JSTOR Archive is a trusted digital repository providing for long-term preservation and access to leading academicjournals and scholarly literature from around the world. The Archive is supported by libraries, scholarly societies, publishers,and foundations. It is an initiative of JSTOR, a not-for-profit organization with a mission to help the scholarly community takeadvantage of advances in technology. For more information regarding JSTOR, please contact support@jstor.org.http://www.jstor.orgThu Nov 1 15:56:05 2007

Does corporate ownership structure affect its strategy towards diversification

We claim that there is a link between corporate control structure and managers’ strategy towards unrelated mergers and risk diversification. Companies with greater ownership concentration are less diversified. Evidence also shows that corporate diversification generally results in value loss while focussing is value increasing. This highlights the potentially detrimental effect of agency problems on corporate strategy. Copyright

The Effects of Cross-Border Bank Mergers on Bank Risk and Value

This paper examines the effects of cross-border bank mergers on the risk and (abnormal) returns of acquiring banks. We find that overall, the acquirers risk neither increases nor decreases. In particular, on average neither their total risk nor their systematic risk falls relative to banks in their home banking market. The abnormal returns to acquirers are negative and significant, but are somewhat higher when risk increases relative to banks in the acquirer s home country.

Stock market microstructure and return volatility: Evidence from Italy

Abstract This paper studies the impact of the stock market microstructure on return volatility and on the value discovery process in the Milan Stock Exchange. The primary trading mechanism employed by this exchange is a call market, which is usually preceded and followed by trading in a continuous market. We find that the opening transaction in the continuous market has the highest volatility, and that opening the market with the call transaction seems to produce relatively lower volatility. In the closing transaction, investors correct perceived errors or noise in the prices set at the call. The implications of the results for market design are examined.

Liquidity and the 1987 stock market crash

T he Crash of October 1987 was a puzzling event puzzling not only for what happened on October 19, but also for what subsequently did not happen. In spite of the magnitude and momentum of the crash, its effect was limited primarily to the financial markets, while the economy as a whole did not change its course. And, although the ”bad news” that was supposed to be predicted by the crash has apparently not materialized, the market suffered a lasting decline after October of 1987. This article advances a liquidity theory of the crash, proposing that the price decline in October 1987 reflects, at least in part, a revision of investors’ expectations about the liquidity of the equity markets. Amihud and Mendelson [1986a, 1986b, 19891 have shown that the market price of stocks is positively associated with their liquidity (after controlling for risk). Given this relationship, when the liquidity of assets turns out to be less than had been expected, their price should decline. We suggest that the main news that caused the prolonged decline in stock prices was the crash itself that is, the realization that financial markets are not as liquid as previously assumed. Investors recognized that stock prices should reflect a larger discount for the costs of illiquidity, which turned out to be much higher than had been expected before the crash. Partial recovery following the crash reflects an upward reevaluation of the liquidity of the markets -that is, investors recognized that while the markets are not as liquid as had been assumed prior to the crash, they are also not as illiquid as when there was the possibility of closing the markets altogether. These illiquidity problems, reflected in wider spreads between the quoted bid and ask prices, have persisted long after the crash, and market impact estimates have stayed significantly larger than they had been prior to the crash.’ Thus, the crash and subsequent events have produced new information about the markets themselves rather than fundamental news about the economy. Part of the liquidity-related price decline on October 19, 1987, was temporary. Unexpected sale pressure, even absent any negative information, can generate a temporary negative price impact, as we sometimes observe in block sales. But much of the effect was permanent. Investors realized that they may well have to pay a larger discount when they wish to sell stocks in a hurry. These illiquidity costs result in a stream of future cash outflows that translate into a loss of value.2 In general, illiquidity reflects the difficulty of converting cash into assets and assets into cash, or the costs of trading an asset in the market. Some of the costs of illiquidity are explicit and easy to measure, while others are more subtle. These costs include the bid-ask spread, market-impact costs, delay and search costs, and brokerage commissions and fees. These components of illiquidity cost are highly correlated: Stocks that have high bid-ask spreads also have high transaction fees and high search and market-impact costs, and are thinly traded (McInish and Wood [1989]). When the bid-ask spread widens, it signals that immediacy of execution is more costly,

Price Smoothing and Inventory

This paper explains the phenomenon of price rigidity (or price smoothing) as the outcome of the optimal inventory policy of a multi-period profit-maximizing firm under demand and output uncertainties. Price smoothing may be manifested in two forms. First, price changes may be moderated with respect to those implied by the demand function; and second, the firm may choose to restrict price fluctuations by establishing upper and/or lower bounds on prices. We show that the extent of the asymmetry in price smoothing depends on the relationship between the inventory holding cost and the backlog penalty cost. Our model accommodates a wide range of price behaviour as observed in empirical studies on the issue.