Scaling for Residual Variance Components of Ordered Category Responses in Generalised Linear Mixed Multilevel Models

A method is proposed that enables changes in variance components to be computed from the results of fitting ordered response generalised models with multilevel and random effects. This deals with the rescaling of the response that occurs as we add new features to a developing model.     

Net Greenhouse Gas Emissions and the Economics of Annual Crop Management Systems

The aim of this study was to evaluate the relative economic profitability and net greenhouse gas (GHG) abatement potential of alternative tillage and cropping systems. A simulation model was parameterized using biophysical and economic data representing different crop rotations under conventional, minimum, and zero tillage cropping systems, in the Black soil zone of Saskatchewan. This model was used to estimate the relative potential of each of the management practices to sequester carbon and to emit GHG including, nitrous oxide and carbon dioxide. The model also provided estimates of the relative profitability of each of the management practices over time horizons of 30 years. These simulation results were used to develop trade-off functions reflecting net income and net GHG abatement for each cropping system. An income risk measure was incorporated to facilitate an analysis of the relative economic attractiveness of the simulated cropping systems. Furthermore, sensitivity analysis was performed on nitrous oxide emission coefficients (an area of significant uncertainty in the literature) and on weather patterns to reflect uncertain future climate change impacts. Results indicated that net GHG emissions were relatively lower for reduced tillage management, while conventional tillage may be relatively more attractive from an economic perspective. However, results also indicated that such economic factors as risk and economies of size may have a significant influence on this latter result.     

An Empirical Taxonomy of Supply Chain Management Practices

We develop an empirical taxonomy of supply chain management (SCM) practices grounded in the capability‐based view. Three groups—transactional SCM, translational SCM, and relational SCM—were identified using cluster analysis of data collected from over 200 U.S. manufacturing firms. We explain the differences among these groups and their relationship to improvements in supplier and buyer performance. Finally, we discuss implications for research and practice in SCM.     

Use of opioid substitution therapies in the treatment of opioid use disorder: results of a UK cost-effectiveness modelling study

Aims: This study investigated the cost-effectiveness of buprenorphine maintenance treatment (BMT) and methadone maintenance treatment (MMT) vs no opioid substitution therapy (OST) for the treatment of opioid use disorder, from the UK National Health Service (NHS)/personal social services (PSS) and societal perspectives over 1 year.

Methods: Cost-effectiveness of OST vs no OST was evaluated by first replicating and then expanding an existing UK health technology assessment model. The expanded model included the impact of OST on infection rates of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection.

Results: Versus no OST, incremental cost-effectiveness ratios (ICERs) for BMT and MMT were £13,923 and £14,206 per quality-adjusted life year (QALY), respectively, from a NHS/PSS perspective. When total costs (NHS/PSS and societal) are considered, there are substantial savings associated with adopting OST; these savings are in excess of £14,032 for BMT vs no OST and £17,174 for MMT vs no OST over 1 year. This is primarily driven by a reduction in victim costs. OST treatment also impacted other aspects of criminality and healthcare resource use.

Limitations: The model’s 1-year timeframe means long-term costs and benefits, and the influence of changes over time are not captured.

Conclusions: OST can be considered cost-effective vs no OST from the UK NHS/PSS perspective, with a cost per QALY well below the UK’s willingness-to-pay threshold. There were only small differences between BMT and MMT. The availability of two or more cost-effective options is beneficial to retaining patients in OST programs. From a societal perspective, OST is estimated to save over £14,032 and £17,174 per year for BMT and MMT vs no OST, respectively, due to savings in victim costs. Further work is required to fully quantify the clinical and health economic impacts of different OST formulations and their societal impact over the long-term.     

Optimal use of forecasts in economic policy decisions: An empirical test

A criterion for optimal use of forecasts of exogenous variables in a linear policy model with quadratic preferences is given, based on Johansen (1972). By calculating regressions of observed values with respect to raw forecast values used in the observation period, equations are established which can be used to transform raw forecasts into ‘certainty equivalents’. The method is applied to data from national budgeting and corresponding national accounts in Norway 1948–-1971. Especially the forecasts for the volume of exports, but also for import prices, could be considerably improved, for policy purposes in the context of the model of the type mentioned, by the transformation described. Some of the forecasts, when optimally transformed, should be permitted to fluctuate more strongly and thereby influence policy more strongly. Some tentative results for Sweden and the Netherlands are briefly mentioned and compared with the evidence for Norway.     

国际油气生产者协会(OGP)与石油天然气工业用标准

首先OGP是什么?1974成立的国际石油天然气生产者协会。OGP成员包括私有的和国有的石油天然气公司、服务公司、国际和地区性协会。协会的成员可生产世界上一半以上的石油和大约三分之一的天然气。办公室位于伦敦和布鲁塞尔。OGP的愿望为世界上所有的上游公司而工作,推进可靠且可