As the amount of information is rapidly growing, and ubiquitous urban environments are emerging, the question which kind of information to provide is a major challenge for commercial and public travel-information service providers alike. This paper reports the analyses of recent data, collected in Metropolitan Seoul, about the acquisition of travel information. The study applies CHAID analysis to find homogeneous segments in travel information acquisition. Findings indicate that contextual variables are crucial to explain information acquisition behaviour, depending on decision context. The implication is that both socioeconomic and contextual variables are important to better understand the acquisition (and provision) of travel information. The results have important implications for managers and policy-makers, in particular in the way they respond to dynamic, contextual market segmentation. 相似文献
For ridge regression the degrees of freedom are commonly calculated by the trace of the matrix that transforms the vector of observations on the dependent variable into the ridge regression estimate of its expected value. For a fixed ridge parameter this is unobjectionable. When the ridge parameter is optimized on the same data, by minimization of the generalized cross validation criterion or Mallows \(\hbox {C}_{L}\), additional degrees of freedom are used however. We give formulae that take this into account. This allows of a proper assessment of ridge regression in competitions for the best predictor. 相似文献
This article analyzes the relationship between gold quoted on the Shanghai Gold Exchange and Chinese sectorial stocks from 2009 to 2015. Using different copulas, our results show that there is weak but significant tail dependence between gold and Chinese sectorial stock returns. This means that the dependence between extreme movements of the two assets is not pronounced and confirms the role of gold as a safe haven asset. Based on analyzing the efficient frontier, CCC-GARCH optimal weights, hedge ratios and hedging effectiveness, we further show that adding gold into Chinese stock portfolios can help to reduce their risk. Gold appears to be the most efficient diversifier for stocks of the materials sector and the less efficient for the utilities sector. As a robustness check, we also compare gold to oil and indicate that gold is more efficient than oil in the diversification of Chinese stock portfolios.
Scenarios are claimed to support strategic decision makers. They are especially effective in dealing with uncertainties. This paper addresses some drawbacks of the conventional scenario method, which is especially directed at handling these uncertainties, and indicates possible avenues for methodological adaptations. We take the approach, which rests in the Shell tradition, as exemplary for our discussion on the mainstream scenario methodology. This approach has some limitations when it comes to dealing with simultaneous trends and countertrends, and trends or clusters of trends that are not thought of beforehand, especially the methodological requirements of causality and consistency, which might be limiting factors in this respect. This paper indicates alternative ways for scenario construction. It discusses the use of either recombinant scenarios, context scenarios, or inconsistent scenarios and/or combinations of these scenarios. These options explicitly incorporate the notion of ‘paradoxical trend’ as the codriver of future developments into the methodology. 相似文献
The introduction of the euro generated substantial interest in the impact of currency unions (CUs) on trade flows. Initial estimates suggested a tripling of trade, which gave rise to a literature in search of “more reasonable” CU effects. Theoretical derivations of the gravity model highlight, however that the CU literature neglects to control simultaneously for general equilibrium effects (multilateral resistance) and unobserved bilateral heterogeneity among trade partners. Once we introduce the appropriate controls, CU trade effects are shown to range around 50%. We also highlight that the practice of reporting average CU effects generates misleading results. The average effect is shown to be a composite of disparate individual CU effects ranging from 40% (euro) to about 100% (Central African franc). 相似文献
A Geographical Information System (GIS) has recently been developed for the assessment of the agricultural potential of the Southern African Development Community (SADC) region. The main value of this GIS is the integration of agricultural resource information from the SADC countries in order to support regional planning. The development of GIS technology makes it possible to compile, store, retrieve, analyse and display vast quantities of spatial data on, inter alia, the climate, topography, soils and infrastructure of the region. This article aims to give background information on the nature and general application of a GIS. Attention is given to the capabilities of a GIS, the spatial questions that drive analyses, basic database requirements, analytical and operational functions, as well as the applications of a GIS in land reform. More detail on the spatial agricultural resource data captured and its use by means of the SADC GIS will be described in a later article. 相似文献
Monetary budgets influence activity participation and related travel as they demarcate limits on how people organize their activities in time and space. In this paper, we are interested in money allocation to out-of-home leisure activities and how this is affected by duration, sociodemographics, and time-location variables. Analyses were carried out by applying a seemingly unrelated regression model to a leisure activity data set. The analyses revealed that expenditures for out-of-home leisure activities are influenced by the variables mentioned above. Moreover, the results indicate that there is a substitution between expenditure of each activity. 相似文献
This study focuses on the dynamics of the gold price against bonds, stocks and exchange rates based on a disaggregation of the underlying relationships across different frequencies applying a wavelet decomposition. To analyze joint extreme movements (i.e. tail dependence), we adopt a copula approach, which helps us to assess the dependence between the returns of gold and other assets in calm and turmoil market times and therefore the hedge and safe haven functions of gold. We also examine whether gold prices are directly affected by changes in macroeconomic uncertainty, economic policy uncertainty and/or CPI forecasters disagreement. Analyzing data for nine economies for a sample period starting in 1985, we find that the role of gold changes significantly after the collapse of Lehman Brothers in 2008. Gold is unable to serve as a hedge or safe haven in the classical sense while the findings for the period prior to 2008 mostly suggest that gold is able to shield investors. Uncertainty measures display a surprising and time-varying relationship with the path of the gold price. While economic policy uncertainty is positively correlated with gold price changes, macroeconomic uncertainty and inflation uncertainty among forecasters are both negatively related to gold price changes. 相似文献
What are the costs and benefits of mandatory dividend rules? On the one hand, they make it harder for controlling shareholders to divert corporate assets. On the other hand, they reduce the internal funds available for firms to invest, possibly leading to the loss of valuable projects. To assess this trade-off, we look at investment and dividend decisions in a sample of public firms in Brazil. We show that a significant fraction of these firms use loopholes of Brazil's mandatory dividend rules to avoid paying dividends. And yet, the dividend rules are effective. They help explain why the average dividend yield in Brazil is higher than in the U.S., without making it harder for firms to invest. 相似文献