Explaining ethnic violence in black Africa: Independence to 1979

The underlying causes of ethnic mobilisation have been addressed by theories of cultural pluralism, ethnic competition, differential economic incorporation and modernisation. Up to now, no quantitative cross‐national study has tested all these perspectives simultaneously. The results of this study provide support for some aspects of the different theories, with the exception of the theory of differential economic incorporation. The results of the synthetic model stress the importance of examining multiple perspectives in order to avoid only partially correct representations of the historical reasons behind ethnic conflict in black Africa.     

Private borrowing during the financial revolution: Hoare's Bank and its customers, 1702–241

The financial revolution improved the British government's ability to borrow, and thus its ability to wage war. North and Weingast argued that it also permitted private parties to borrow more cheaply and widely. We test these inferences with evidence from a London bank. We confirm that private bank credit was cheap in the early eighteenth century, but we argue that it was not available widely. Importantly, the government reduced the usury rate in 1714, sharply reducing the circle of private clients that could be served profitably.     

Hedging,Financing and Investment Decisions: A Simultaneous Equations Framework

We empirically investigate the interactions among hedging, financing, and investment decisions. We argue that the way in which hedging affects a firm's financing and investing decisions differs for firms with different growth opportunities. We find that high growth firms increase their investment, but not leverage, by hedging. However, we also find that firms with few investment opportunities use derivatives to increase their leverage.     

Through Trial and Error to Collusion*

In this article we study a very simple trial and error learning process in the context of a Cournot oligopoly. Without any knowledge of the payoff functions players increase, respectively decrease, their quantity as long as this leads to higher profits. We show that despite the absence of any coordination or punishing device this process converges to the joint‐profit‐maximizing outcome.     

成本上升侵蚀中国竞争优势

在上海的宜家商店，售价1．4美元的泰迪熊可能是全城最便宜的了，但它们不是产自中国，而是在印度尼西亚缝制和填充的。     

Moral Hazard and Risk Management in Agri‐environmental Policy

This paper develops the key finding of Ozanne, Hogan and Colman (2001) that risk aversion among farmers ameliorates the moral hazard problem in relation to agrienvironmental policy compliance. It is shown that risk averse farmers who face uncertainty in their production income are more likely to comply with such a policy as a means of risk management. In addition, it is shown that a principal who has control over both the level of monitoring and the size of penalty, if detected, can reduce non‐compliance by adjustments to these instruments which increase the variance of farmers' income but leave the expected penalty unchanged. It is concluded that risk management by both principals and agents has the potential to diminish the moral hazard problem, especially given proposed developments in agri‐environmental policy in the European Union.     

A theoretical framework to evaluate different margin‐setting methodologies

The margin system is the first line of defense against the default risk of a clearinghouse. From the perspectives of a clearinghouse, the utmost concern is to have a prudential system to control the default exposure. Once the level of prudentiality is set, the next concern will be the opportunity cost of the investors, because high opportunity cost discourages people from hedging futures, and thus defeats the function of a futures market. In this article, we first develop different measures of prudentiality and opportunity cost. We then formulate a statistical framework to evaluate different margin‐setting methodologies, all of which strike a balance between prudentiality and opportunity cost. Three margin‐setting methodologies, namely, (1) using simple moving averages; (2) using exponentially weighted moving averages; (3) using a GARCH approach, are applied to the Hang Seng Index futures. Keeping the same prudentiality level, it is shown that the one using a GARCH approach by and large gives the lowest average overcharge. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:117–145, 2004     

The index futures markets: Is screen trading more efficient?

This article uses a nonparametric test based on the arc‐sine law (see, e.g., Feller, 1965 ), which involves comparing the theoretical distribution implied by an intraday random walk with the empirical frequency distribution of the daily high/low times, in order to address the question of whether the abandonment of pit trading has been associated with greater market efficiency. If market inefficiencies result from flaws in the market microstructure of pit trading, they ought to have been eliminated by the introduction of screen trading. If, on the other hand, the inefficiencies are a reflection of investor psychology, they are likely to have survived, unaffected by the changeover. We focus here on four cases. Both the FTSE‐100 and CAC‐40 index futures contracts were originally traded by open outcry and have moved over to electronic trading in recent years, so that we are able to compare pricing behavior before and after the changeover. The equivalent contracts in Germany and Korea, on the other hand, have been traded electronically ever since their inception. Our results overwhelmingly reject the random‐walk hypothesis both for open‐outcry and electronic‐trading data sets, suggesting there has been no increase in efficiency as a result of the introduction of screen trading. One possible explanation consistent with our results would be that the index futures market is characterized by intraday overreaction. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:337–357, 2004     

An empirical analysis of the relationship between the hedge ratio and hedging horizon: A simultaneous estimation of the short‐ and long‐run hedge ratios

This article analyzes the effects of the length of hedging horizon on the optimal hedge ratio and hedging effectiveness using 9 different hedging horizons and 25 different commodities. We discuss the concept of short‐ and long‐run hedge ratios and propose a technique to simultaneously estimate them. The empirical results indicate that the short‐run hedge ratios are significantly less than 1 and increase with the length of hedging horizon. We also find that hedging effectiveness increases with the length of hedging horizon. However, the long‐run hedge ratio is found to be close to the naïve hedge ratio of unity. This implies that, if the hedging horizon is long, then the naïve hedge ratio is close to the optimum hedge ratio. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:359–386, 2004