A Comparison of the Power of Parametric and Nonparametric Tests of Location Shift for Event Studies

This paper distinguishes between testing approach (parametric t, sign, cross-sectional rank, and longitudinal rank) and test type (conventional, standardized, and weighted least squares). Similar tests (i.e., tests of the same type) are compared for each testing approach using constant and unequal shift models. Thus the results given here are free of confounding effects present in prior comparisons of dissimilar tests. While all the tests compared are sensitive to the underlying location shift model, if the shift is independent of the security standard deviation, then the weighted least squares longitudinal rank test is most. powerful.     

Dynamic modelling of agroforestry and soil fertility interactions: implications for multi-disciplinary research policy

This paper attempts to contribute to one of the major aspects of international research agenda in agroforestry. A general framework is developed in this paper to capture the dynamic interactions of various components of agroforestry system. Using a multi-seasonal model of agroforestry, the competition among the system components in resource and input use and the trade-offs between different outputs of agroforestry system are analyzed. Policy implications for multi-disciplinary research are derived. It is argued that quantifying the potential benefits of agroforestry system requires reformulation of existing economic methods of analyzing agroforestry technology to contribute to the fuller understanding of the dynamic interactions among its various components.     

Model selection in univariate time series forecasting using discriminant analysis

When a large number of time series are to be forecast on a regular basis, as in large scale inventory management or production control, the appropriate choice of a forecast model is important as it has the potential for large cost savings through improved accuracy. A possible solution to this problem is to select one best forecast model for all the series in the dataset. Alternatively one may develop a rule that will select the best model for each series. Fildes (1989) calls the former an aggregate selection rule and the latter an individual selection rule. In this paper we develop an individual selection rule using discriminant analysis and compare its performance to aggregate selection for the quarterly series of the M-Competition data. A number of forecast accuracy measures are used for the evaluation and confidence intervals for them are constructed using bootstrapping. The results indicate that the individual selection rule based on discriminant scores is more accurate, and sometimes significantly so, than any aggregate selection method.     

Hybrid Choice Models: Progress and Challenges

We discuss the development of predictive choice models that go beyond the random utility model in its narrowest formulation. Such approaches incorporate several elements of cognitive process that have been identified as important to the choice process, including strong dependence on history and context, perception formation, and latent constraints. A flexible and practical hybrid choice model is presented that integrates many types of discrete choice modeling methods, draws on different types of data, and allows for flexible disturbances and explicit modeling of latent psychological explanatory variables, heterogeneity, and latent segmentation. Both progress and challenges related to the development of the hybrid choice model are presented.     

Whither the pin factory? Modern food supply chains and specialization in India

What is the relationship between smallholder participation in modern food supply chains and their degree of economic specialization? We investigate this research question by looking at whether there is a systematic relationship between whether a household grows crops for a supermarket chain—participation in the supermarket channel—and how concentrated among fewer crops are that household's total landholdings and its output. Using longitudinal data from India, we find that there is no relationship between whether a household participates in the supermarket channel and that household's Herfindahl–Hirschman index for land, but there is a robust statistically significant and negative relationship between whether a household participates in the supermarket channel and that household's Herfindahl–Hirschman index for output. These findings hold true at both the extensive margin (i.e., when considering whether a household participates in the supermarket channel) and the intensive margin (i.e., when considering how much of a household's marketed output is sold through the supermarket chain). This suggests that instead of fostering a greater degree of specialization, participation in modern food supply chains might lead to greater diversification.     

Speed-profile-based road segmentation for accident occurrence modelling for hilly terrains

Modelling the accident occurrences per unit length of the road requires segmentation of road stretch. In the case of hilly terrains, homogeneity-based approach results in extremely small sections thus creating a biased accident data. This result is due to the high variations in geometry along the length of the road stretch. Constant length sections do not consider the effect of road's characteristics, hence may lead to undesirable results. It is hypothesized that the speed profile of a vehicle moving in free-flow conditions is governed by the road geometry as well as the road side environment. In this paper, a new methodology based on speed profile of a test vehicle (passenger car) has been proposed for segmenting a road stretch passing through hilly terrain. Comparative analysis of the results obtained from the constant length segmentation approach and the proposed approach shows that the later approach is producing statistically better results. Relatively more parameters were found to be statistically significant in the model based on speed-profile-based segmentation. Grade length, which could be one of the major parameters in hilly terrains, was found to be statistically significant only in the model based on speed-profile-based segmentation.     

A new approach to determining sectoral priorities in an economy: input–Output elasticities

This paper uses input–Output elasticities to identify important economic sectors. Elasticities of output employment and income are used to identify key sectors of the Greek economy. A comparison of the rankings of economic sectors based on input–output elasticities with those based on net backward linkages indicates significant divergence in sectoral rankings obtained from the two approaches. The elasticity approach yields more consistent estimates of sectoral output employment and income potentials than the net backward linkage approach. Measured in terms of the potential to generate output employment and income agriculture services and textiles are found to be the key sectors for the Greek economy.     

Race, Inequality, and Anti-Chinese Violence in the Netherlands Indies

Movements in wages for subjects of the Netherlands Indies for the period 1908-1917 are analyzed. The analysis reveals a sharp increase in inequality between the ethnic indigenous and Chinese communities between 1910 and 1916, the period of the birth and rise of the anti-Chinese Sarekat Islam movements in Java. It also reveals that this inequality was most severe in a number of residencies of Java, where the movements first took hold. While there is statistical evidence of a link between interracial wage differentials and anti-Chinese violence, there is no link between absolute wages and violence. This evidence suggests that “relative deprivation” is important in understanding ethnic tension.     

Trade Destruction and Trade Diversion: Evidence from China

Over the past three decades, we have seen a dramatic increase in the incidence of temporary trade barriers such as antidumping duties and countervailing duties. China has been at the receiving end of a large number of such measures. In this paper, we study how China's exports to its major trade partners have been affected when its major trade partners have used these measures either against China or against other countries. We find that Chinese exports to the country that imposed an antidumping duty decreased by approximately 35 percent. At the same time, an antidumping duty used by the importing country that was directed towards other countries but not against China led to an approximate 30‐percent increase in China's exports to the policy‐imposing country. These results remain robust across various specifications. Our findings have important policy implications. In particular, the magnitude of these effects highlights why it is important to curb the recent widespread use of these barriers.