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     

Transforming Local Government: Innovation and Modernization

This article is based on research investigating why local authorities innovate and what happens when they do. The authors show how local authorities have responded to the current normative climate for innovation, and explore the interaction between central policy and local action. The article demonstrates the importance of the policy climate set by central government in fostering—or constraining—innovation at a local level.     

The dynamics of positive action in UK trade unions: the case of women and black members

This paper considers positive action strategies amongst UK trade unions, aimed at increasing membership and levels of participation and representation among women and black workers. It provides an overview of women’s, black members’ and race structures within large Trades Union Congress unions and a detailed case study of one large UK trade union. We find that there are salient differences in the way that unions approach issues of gender equality, compared with the approach adopted towards race equality. The paper explores possible explanations, justifications and implications of these differences.     

General‐to‐Specific Model Selection Procedures for Structural Vector Autoregressions*

Structural vector autoregressive (SVAR) models have emerged as a dominant research strategy in empirical macroeconomics, but suffer from the large number of parameters employed and the resulting estimation uncertainty associated with their impulse responses. In this paper, we propose general‐to‐specific (Gets) model selection procedures to overcome these limitations. It is shown that single‐equation procedures are generally efficient for the reduction of recursive SVAR models. The small‐sample properties of the proposed reduction procedure (as implemented using PcGets) are evaluated in a realistic Monte Carlo experiment. The impulse responses generated by the selected SVAR are found to be more precise and accurate than those of the unrestricted VAR. The proposed reduction strategy is then applied to the US monetary system considered by Christiano, Eichenbaum and Evans (Review of Economics and Statistics, Vol. 78, pp. 16–34, 1996) . The results are consistent with the Monte Carlo and question the validity of the impulse responses generated by the full system.     

WORLD OUTLOOK

Events in the Gulf have finally brought an end to the world economic boom of the last eight years. The oil price shock itself is only partly responsible for the downturn. The previous tightening of monetary policy in the face of inflationary pressures and the end of a rapid period of credit and asset price expansion had severely weakened the ability of some economies to respond to the shock. This is reflected in the diversity of response, most obviously in the United States where Fed fine tuning and the credit crunch have already weakened the economy. The rise in oil prices has led to a sudden collapse in consumer confidence and a swift cutback in output. Although we do not expect the recession to be deep, the financial problems will delay recovery. The Japanese economy was already in financial difficulties before the shock, although the real economy was stronger and here we expect a sharp deceleration from almost 6 per cent growth last year to around 3.5 per cent. In contrast the German economy, partly shielded by the substantial appreciation of the DM over the last year, has been affected less by the oil price shock and we expect the consumer and investment boom to continue this year as the economies merge. This provides a welcome boost to other European economies.