Effects of scale economies and production seasonality on optimal hub locations: the case of regional fresh produce aggregation

Interest in supporting local and regional food systems is rising and food hubs have attracted considerable attention among Federal, State, and local policymakers. This study explores the problem of endogenous hub location in fresh produce value chains in the Northeastern United States. To overcome limitations in the literature, we incorporate the effects of economies of scale and production seasonality into our models. Three experimental models are designed to examine the effects of alternatively applying yearly, quarterly, and monthly data on model solutions. We explicitly assess how interactions of scale economies and seasonality influence the structure and spatial attributes of an optimal regional produce aggregation hub system. The three models generate marketed different solutions and in many respects they lead to different conclusions about developing local/regional supply chains. The monthly model allows for production seasonality and actual hub operation cycle frequency and thus leads to more efficient hub solution with rich policy implications.     

Exploring the male Chinese tourists’ motivation for commercial sex when travelling overseas: Scale construction and validation

Sex and tourism has long been understudied. Little is known about tourists' motivations for consuming commercial sex while travelling, and even less, if indeed anything, is known about that of Chinese outbound tourists in particular. Based on twenty interviews and two surveys with a sample of 534 male Chinese tourists who had engaged in commercial sex when travelling overseas in the previous 12 months, this study aimed first to explore why male Chinese tourists travelled overseas and purchased commercial sex, and second to construct a comprehensive scale for measuring male tourists’ motivations for overseas commercial sex. With acceptable reliability and validity, the measurement scale yielded in this study consisted of eight motivation dimensions labelled as socialisation, relaxation and escape, travel-related novelty, sexual desire fulfillment/excitement seeking, sex-related learning, sexual mastery, social prestige, and business/pragmatic purpose. Both the theoretical and methodological implications related to the developed scale are also discussed.     

Panel LM unit root tests with level and trend shifts

This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.     

Cross‐Functional Integration: Concept Clarification and Scale Development

The centrality of cross‐functional integration (CFI) to supply chain theory and practice has long been recognized. Yet researchers continue to struggle with consistently defining or measuring the CFI construct, thus limiting the utility of CFI research. This research develops (1) a comprehensive definition of CFI that synthesizes previous supply chain research and (2) a valid set of scale items that measure the conceptual domain outlined by this definition. The goal is to build a common foundation for extending knowledge on CFI's antecedents and consequences, and ultimately to improve scholars’ ability to guide a broader practitioner community still struggling to achieve integration in their organizations.     

A play-the-winner-type urn design with reduced variability

We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns more subjects to the better treatment. Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions.     

服务业集聚与产业结构优化关系探究

随着全球化进程的不断加快，服务业集聚已经成为人们普遍关注的话题。产业集聚在获得规模效应的同时避免了垄断现象的产生，服务业集聚不但拥有这样的优势，而且还有自己独特的形成和发展特点。从产业结构的优化角度切入，借助区位商和专门化率等分析指标，以江苏省和上海市为例，对服务业集聚的形成进行理论和实证分析，提出产业结构的优化对于服务业集聚的形成和发展有着积极的作用。合理的产业结构能够为服务业集聚提供坚实的基础，各地区应该根据各自的产业特点积极的进行优化，催生服务业集聚，加快本地区经济的进一步发展。     

Estimation of the mean in ranked set sampling with non responses

The estimation of the population mean when ranked set sampling [rss] is used for selecting the sample and non responses [nr] are present, is studied. The nr stratum is sub sampled using simple random sampling with replacement. Two strategies are analyzed. One of them is based on the selection of a sub sample from the nr in each cycle. The other uses sub samples selected among the nr in each rank.  The accuracy of the proposed estimators is characterized by the corresponding expected variances. Simulations and real life data are used for analyzing the behavior of them. Acknowledgements: This paper was developed partially during the visit of the author to Université des Antilles et Gouyane. The author gratefully acknowledges the helpful suggestions of the referees and thanks the support of DAAD for visiting Humboldt University where a version of the paper version was made.     

Measuring the Impact of Regulation: A Study of Canadian Basic Cable Television

We evaluate the appropriateness of regulation within the Canadian cable television industry by applying both parametric and non-parametric approachesto measure scale efficiency. Although we begin with a sample offering adequatedegrees of freedom for parametric estimation, important policy issues lead us toconsider further estimation over sub-samples. Since some of these sub-samplesare small enough that parametric models cannot guarantee reliable estimates, weobtain production characteristics non-parametrically through data envelopmentanalysis. The nonparametric results for scale efficiency support the parametricresults. We find evidence against a natural monopoly argument that might havejustified continuation of the mandated monopolization of Canadian cable televisionservice. By the end of the sample period, there were no longer substantial economiesof scale in most relevant markets.     

How Issue Size, Risk, and Complexity are Influencing External Financing Costs: German IPOs Analyzed from an Economies of Scale Perspective

This paper is focused on the cost of raising capital in Germany. A cross-sectional analysis of flotation cost data for 117 IPOs over the years 1993–1998 is presented. We find average flotation costs to be 7.77 percent of gross proceeds, while underwriting fees average 5.01 percent. Our results extend the literature in two important directions. First, contrary to the conventional economies of scale view we find marginal spreads to be rather constant in gross proceeds and to be higher for more risky and more complex offerings. Fixed costs amount to 5 to 9 percent of underwriting fees. Second, by applying a principal component analysis we find issue size, an issuer risk factor, and an offering method complexity factor to have an economicaly meaningful impact on underwriting fees.