Global logistics indicators, supply chain metrics, and bilateral trade patterns

Past research into the determinants of international trade highlighted the importance of the basic spatial gravity model augmented by additional variables representing sources of friction. Studies modeled many sources of friction using various proxies, including indices based on expert judgment in some cases. This paper focuses on logistics friction and draws on a data set recently compiled by the World Bank with specific quantitative metrics of logistics performance interms of time, cost, and variability in time. It finds that the new variables that relate directly to logistics performance have a statistically significant relationship with the level of bilateral trade. It also finds that a single logistics index can capture virtually all of the explanatory power of multiple logistics indicators. The findings should spur public and private agencies that have direct or indirect power over logistics performance to focus attention on reducing sources of friction so as to improve their country's ability to compete in today's global economy. Moreover, since the logistics metrics are directly related to operational performance, countries can use these metrics to target actions to improve logistics and monitor their progress.Common Carriers Industry,Transport and Trade Logistics,Economic Theory&Research,Free Trade,Trade Policy

The Role of Slotting Fees in the Coordination of Assortment Decisions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72029/1/j.1937-5956.2009.01039.x.pd

Lipoteichoic acid-antilipoteichoic acid complexes induce superoxide generation by human neutrophils

Human neutrophils (PMNs) which have been incubated with lipoteichoic acid (LTA) from group A streptococci generated large amounts of Superoxide (O 2 − chemiluminescence and hydrogen peroxide when challenged with anti-LTA antibodies. Cytochalasin B further enhanced O 2 * generation. The onset of Of generation by the LTA-anti-LTA complexes was much faster than that induced by BSA-anti-BSA complexes. LTA-treated PMNs generated much less O 2 * when challenged with BSA complexes, suggesting that LTA might have blocked, nonspecifically, some of the Fc receptors on PMNs. PMNs treated with LTA-anti-LTA complexes further interacted with bystander nonsensitized PMNs resulting in enhanced Of generation, suggesting that small numbers of LTA-sensitized PMNs might recruit additional PMNs to participate in the generation of toxic oxygen species. Protelolytic enzyme treatment of PMNs further enhanced the generation of O 2 − by PMNs treated with LTA-anti-LTA. Superoxide generation could also be induced when PMNs and anti-LTA antibodies interacted with target cells (fibroblasts, epithelial cells) pretreated with LTA. This effect was also further enhanced by pretreatment of the target cells with proteases. PMNs incubated with LTA released lysosomal enzymes following treatment with anti-LTA antibodies. The amounts of phosphatase, Β -glucoronidase, N -acetylglucosaminidase, mannosidase, and lysozyme release by LTA-anti-LTA complexes were much smaller than those released by antibody or histone-opsonized streptococci, suggesting that opsonized particles are more efficient lysosomal enzyme releasers. However, since the amounts of O 2 − generated by the LTA complexes equaled those generated by the opsonized particles, it is assumed that the signals for triggering a respiratory burst and lysosomal enzyme secretion might be different.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44498/1/10753_2004_Article_BF00914316.pd

Assumption without representation: the unacknowledged abstraction from communities and social goods

We have not clearly acknowledged the abstraction from unpriceable “social goods” (derived from communities) which, different from private and public goods, simply disappear if it is attempted to market them. Separability from markets and economics has not been argued, much less established. Acknowledging communities would reinforce rather than undermine them, and thus facilitate the production of social goods. But it would also help economics by facilitating our understanding of – and response to – financial crises as well as environmental destruction and many social problems, and by reducing the alienation from economics often felt by students and the public

Sequential Decision Problems: A Model to Exploit Existing Forecasters

A sequential decision problem is partitioned into two parts: a stochastic model describing the transition probability density function of the state variable, and a separate framework of decision choices and payoffs. If a particular sequential decision problem is a recurring one, then there may often exist human forecasters who generate quantitative forecasts at each decision stage. In those eases where construction of a mathematical model for predictive purposes is difficult, we may consider using the forecasts and forecast revisions provided by the existing forecasting mechanism as the state variable. The paper considers a specific class of problems in which improved forecasts of some unknown quantity are available before each decision stage. A small number of actual forecasters are studied through analysis of historical data to see whether the data-generating process for forecast changes is quasi-Markovian. The data are generally, although not entirely, consistent with the hypothesis that ratios of successive forecasts are independent variates; their distribution appears to be conditionally Lognormal. Some possible reasons for these results are explored. In cases where the hypothesis holds, a dynamic programming approach to the sequential decision problem may be used to provide optimal decision rules. The usefulness of the approach is illustrated with a numerical example involving crop planning, and the example is extended to explore the effects of using the methodology when the required assumptions do not hold.