Aggregation of exponential smoothing processes with an application to portfolio risk evaluation

In this paper we propose a unified framework to analyse contemporaneous and temporal aggregation of a widely employed class of integrated moving average (IMA) models. We obtain a closed-form representation for the parameters of the contemporaneously and temporally aggregated process as a function of the parameters of the original one. These results are useful due to the close analogy between the integrated GARCH (1, 1) model for conditional volatility and the IMA (1, 1) model for squared returns, which share the same autocorrelation function. In this framework, we present an application dealing with Value-at-Risk (VaR) prediction at different sampling frequencies for an equally weighted portfolio composed of multiple indices. We apply the aggregation results by inferring the aggregate parameter in the portfolio volatility equation from the estimated vector IMA (1, 1) model of squared returns. Empirical results show that VaR predictions delivered using this suggested approach are at least as accurate as those obtained by applying standard univariate methodologies, such as RiskMetrics.     

Price Discovery in the Treasury‐Bill When‐Issued Market

When‐issued (i.e., forward) trading in T‐bills yet to be auctioned provides a unique environment for examining price discovery. Because T‐bills are auctioned in a sealed‐bid process, when‐issued traders cannot observe the spot market price. Yet the forward price must ultimately converge on the auction outcome price. Our results indicate that traders in the when‐issued market “discover” the ultimate auction price. Little evidence is found that standard order flow variables contribute to price discovery. Instead, the ability to observe a few trades with relatively small volume in the when‐issued market is sufficient to discover the auction price resulting from the sealed‐bid process.     

The Economics Olympics: Ranking U.S. Economics Departments Based on Prizes,Medals, and Other Awards

This study ranks the top 25 U.S. economics departments on the basis of four prestigious awards won/held by these departments' current faculty: the Nobel Prize in Economic Sciences, the John Bates Clark Medal, the American Economic Association's (AEA's) Distinguished Fellow Award, and the American Economic Association's Richard T. Ely Lecturer. Based on our methodology, the top economics department is affiliated with the University of Chicago. This distinction stems from its affiliation with six Nobel Prize winners, four Clark Medal winners, and two participants each in the AEA Distinguished Fellow and Richard T. Ely Lecturer categories.     

Trading networks and liquidity provision

We study the profitability of traders in two fully electronic and highly liquid markets: the Dow and Standard & Poor?s 500 e-mini futures markets. Using unique information that identify counterparties to a transaction, we show and seek to explain the fact that the network pattern of trades captures the relations between behavior in the market and returns. Our approach includes a simple representation of how much a shock is amplified by the network and how widely it is transmitted. This representation provides a possible shorthand for understanding the consequences of a fat-finger trade, a withdrawing of liquidity, or other market shock.     

浅谈10kV配电设计

一般情况下,按变压器的效率最高时的负荷率βM来计算变压器容量,计算负荷最好是2倍总功率P总,留有一定的缓冲空间,而母线采用的材料为铜、铝、钢或其他金属。电缆绝缘材料应根据电缆绝缘材料的种类来选用,电缆截面的选择应特别注意电缆允许载流量与敷设环境的温度。     

An investigation of customer order flow in the foreign exchange market

This paper examines the effect that heterogeneous customer orders flows have on exchange rates by using a new, and the largest, proprietary dataset of weekly net order flow segmented by customer type across nine of the most liquid currency pairs. We make several contributions. Firstly, we investigate the extent to which customer order flow can help to explain exchange rate movements over and above the influence of macro-economic variables. Secondly, we address the issue of whether order flows contain (private) information which explain exchange rates changes. Thirdly, we look at the usefulness of order flow in forecasting exchange rate movements at longer horizons than those generally considered in the micro-structure literature. Finally we address the question of whether the out-of-sample exchange rate forecasts generated by order flows can be employed profitably in the foreign exchange markets.     

A Pinch or a Pint? Evidence of Pesticide Overuse in Bangladesh

In a recent survey of 820 rice, potato, bean, eggplant, cabbage, sugarcane and mango farmers in Bangladesh, over 47% of farmers were found to be overusing pesticides. With only 4% of farmers formally trained in pesticide use or handling, and over 87% openly admitting to using little or no protective measures while applying pesticides, overuse is potentially a great threat to farmer health as well as the environment. Pesticide overuse was initially modelled using a three‐equation, trivariate probit framework with health effects and misperception of pesticide risk as endogenous dummy variables. Significance tests revealed that health and misperception were not endogenous to overuse, suggesting a bivariate probit model for health effects and misperception and a separate probit model for overuse. Health effects were found to be a function of the amount of pesticides used in production, nutritional status and income, while misperception of pesticide risk was determined by health impairments from pesticides and the toxicity of chemicals used. Pesticide overuse was significantly explained by variation in misperception, income, farm ownership, the toxicity of chemicals used, crop composition and geographical location. These results highlight the necessity for policymakers to design effective and targeted outreach programmes which deal specifically with pesticide risk, safe handling and averting behaviour. Ideally, the approach would be participatory in nature to address key informational gaps, as well as increasing: farmers’ awareness. The results also point to specific crops and locations experiencing a higher prevalence of overuse. Focusing efforts on these crops and geographical areas may have the most measurable effects on pesticide overuse.     

Pareto improving financial innovation in incomplete markets

Summary. In this paper we develop a differential technique for investigating the welfare effects of financial innovation in incomplete markets. Utilizing this technique, and after parametrizing the standard competitive, pure-exchange economy by both endowments and utility functions, we establish the following (weakly) generic property: Let S be the number of states, I be the number of assets and H be the number of households, and consider a particular financial equilibrium. Then, provided that the degree of market incompleteness is sufficiently larger than the extent of household heterogeneity, S−I≥2H−1 [resp. S−I≥H+1], there is an open set of single assets [resp. pairs of assets] whose introduction can make every household better off (and, symmetrically, an open set of single assets [resp. pairs of assets] whose introduction can make them all worse off ). We also devise a very simple nonparametric procedure for reducing extensive household heterogeneity to manageable size, a procedure which not only makes our restrictions on market incompleteness more palatable, but could also prove to be quite useful in other applications involving smooth analysis. Received: August 14, 1995; revised version: April 14, 1997     

Demographic structure and capital accumulation

This paper develops an overlapping-generations (OLG) model to analyze the consequences of demographic structure changes induced by an exogenous shift in the birth rate. We first show that a finite growth rate of the population that maximizes long-run capital per capita exists. Then, we examine the theoretical properties of this growth rate by showing that: (i) it corresponds to the demographic structure such that the average ages of capital holders and workers are equal; (ii) it is associated to an efficient steady state; (iii) it increases with compulsory transfers from younger to older generations. Finally, we explain why standard OLG models do not exhibit such a growth rate.     

On Combining Partial and Incompatible Information in E-negotiation and E-arbitration

The complexity of the problems to be addressed in an e-democracy framework and the variety of involved stakeholders, with different backgrounds, views and access to information sources, lead us to consider the case in which an e-negotiation should be performed among subjects who have partial, sometimes incompatible, information and can hardly gather to discuss issues together, under the supervision of a facilitator. We propose a statistical method which addresses the issue of partial and incompatible information, merging it and then using it to get a final decision, possibly in an automatic way, through processes of e-negotiation and e-arbitration.