Price limit changes,order decisions,and stock price movements: an empirical analysis of the Taiwan Stock Exchange

Review of Quantitative Finance and Accounting - This study examines the relationships among price limit changes, order submission decisions, and stock returns in the Taiwan Stock Exchange....     

A note on the hedging effectiveness of GARCH models

This note compares the hedging effectiveness of the conventional hedge ratio and time-varying conditional hedge ratios (of which GARCH ratio is a special case). It is shown that, in large sample cases, the conventional hedge ratio provides the best performance. For small sample cases, a sufficiently large variation in the conditional variance of the futures return is required to produce the opposite result. The result is due to the fact that the hedging effectiveness measure is based upon the unconditional variance; meanwhile, the conventional hedge ratio minimizes the unconditional variance and the conditional hedge ratio aims at minimizing the conditional variance.     

Financial assistance for study abroad students: An economic analysis

This paper examines the scholarship payback policy embedded in a study abroad program. A full payback policy requires a student to return the whole amount of the scholarship should he fail to achieve a target post-program performance, whereas a partial payback policy requires a payback amount in proportion to the extent of the under-performance. It is found that, the university should adopt a fixed amount scholarship to maximize the average post-program ability. There is also an optimal partial payback policy.     

Hedging gas bills with weather derivatives

Natural gas company managers concerned with customer satisfaction attempt to minimize the occurrence of extreme bills. Previously, only price fluctuations were addressed with derivative instruments; exchange-traded weather derivatives present a means of hedging exposure to increases in quantity of gas demanded during colder than expected winter months. We model a natural gas company’s ability to adjust for consumer sensitivity and exposure to extreme bills with the use of an optimal mix of weather derivatives and gas pricing derivatives. We find consumer exposure to extreme bills is minimized when the utility uses pricing and weather derivatives.(JEL G11, L51)     

Can modeling the natural gas futures market as a threshold cointegrated system improve hedging and forecasting performance?

The calculation of the hedge ratio, and therefore the effectiveness of the hedge, is dependent upon the correct specification of the relationship between the futures and spot price. Likewise, a forecast of the future spot or futures price is dependent upon the model specification. This article investigates the appropriateness of using a threshold cointegrated model of the natural gas markets as the basis for hedging and forecasting. The findings suggest that the threshold model is more appropriate for longer contract length and that the threshold model does not offer much improvement in hedging or forecasting efficiency.     

Coupling urban expansion models and hydrological models: How important are spatial patterns?

It is well known that urban expansion has a severe impact on the surface water balance by transforming vegetated covers into sealed surfaces. This transformation causes changing fluxes of evapotranspiration, surface runoff and groundwater recharge. In order to estimate the impact of land cover changes on the surface hydrology, hydrological models are often coupled with different types of land cover change models. It is, however, not clear to what extent spatially-explicit urban expansion scenarios provide an added value in comparison with non-spatial urban expansion models at different scale levels. The objective of this paper is to acquire a better insight in the importance of scale effects involved in the coupling of urban expansion scenarios and hydrological models. The relative importance of using different projections of both (i) quantity and (ii) spatial patterns of urban expansion was analysed at four different scale levels. The highly urbanised Flanders–Brussels region was taken as an example application. Twelve different urban expansion scenarios for 2025 and 2050 were developed and subsequently used as an input in a spatially-distributed water balance model. The results obtained suggest that at the level of the Flanders–Brussels region, an accurate estimation of the quantity of urban expansion should get priority over an accurate projection of the spatial patterns. However, the importance of using accurate projections of the spatial pattern of urban expansion increases systematically at local scale levels. A uniform strategy for coupling urban expansion models and hydrological models thus seems inappropriate. These findings are highly relevant for water management and spatial planning policymakers that typically operate at different administrative levels.     

Fractional cointegration and futures hedging

This article examines the performance of various hedge ratios estimated from different econometric models: The FIEC model is introduced as a new model for estimating the hedge ratio. Utilized in this study are NSA futures data, along with the ARFIMA-GARCH approach, the EC model, and the VAR model. Our analysis identifies the prevalence of a fractional cointegration relationship. The effects of incorporating such a relationship into futures hedging are investigated, as is the relative performance of various models with respect to different hedge horizons. Findings include: (i) Incorporation of conditional heteroskedasticity improves hedging performance; (ii) the hedge ratio of the EC model is consistently larger than that of the FIEC model, with the EC providing better post-sample hedging performance in the return–risk context; (iii) the EC hedging strategy (for longer hedge horizons of ten days or more) incorporating conditional heteroskedasticty is the dominant strategy; (iv) incorporating the fractional cointegration relationship does not improve the hedging performance over the EC model; (v) the conventional regression method provides the worst hedging outcomes for hedge horizons of five days or more. Whether these results (based on the NSA index) can be generalized to other cases is proposed as a topic for further research. © 1999 John Wiley & Sons, Inc. Jrl Fut Mark 19: 457–474, 1999     

Organized Complexity in Human Affairs: The Tobacco Industry

How do we explain organized complexity in human affairs? The most common model explain s human organization as the outcome of rational design; order in human affairs arises from the intentions, plans, and orders of those in charge. For organizational complexity on vast scales, this model is insufficient, misleading, and potentially disastrous. An alternative model, based upon self-organization within complex systems, is developed and applied to the tobacco industry. Leaked documents and public testimony point to widespread distortion of information within the tobacco industry. The model developed herein describes such behaviors as emergent outcomes, not reducible to or sufficiently explained by individual fraud and deliberate deceit. Critics of the tobacco industry often fail to appreciate the role of self-organization in complex systems. They presume rational design. Consequently, they imply more intentional deceit, deliberate planning, and conspiracy than needed to explain the distortions that actually occurred. The tobacco industry expresses general phenomena found in many large-scale human systems. This paper describes such phenomena and examines their moral implications.