In this paper, we consider the problem of estimating a selected set of contrasts between v treatments using a block design consisting of b blocks of size k. Traditionally, the construction of A-optimal block designs for such situations has been carried out assuming a fixed effects model. In this paper, we show that A-optimal designs constructed under a fixed effects model are robust in the sense that these designs have maximal minimal efficiency when considered among all available designs and under all possible mixed effects models.
AMS 1991 subject classifications: Primary 62K05; Secondary 62K10 相似文献
This article deals briefly with the most loathsome of business topics — the admission of failure. Rather than actively encouraging project Anti-champions, many organizations experiencing financial duress inadverdently stifle opposing opinion. In some cases recognition is delayed until it is too late. This is unfortunate since failure can be managed like any other business situation. Companies with CEOs that foster open communications between finance and operations are more likely to avoid escalating commitment to failed projects.Prudence is a rich, ugly old maid courted by incapacity.
William BlakeMike Devaney is Associate Professor of Finance at South-East Missouri State University. His primary research interest is real estate finance. He has published in the Journal of the American Real Estate and Urban Economics Association, Journal of Real Estate Research, and The Appraisal Journal to name a few. He also enjoys writing on popular business myth and has published on this subject in Business and Society Review as well as others. 相似文献
Mixed logit models represent a powerful discrete choice analytical model but require assumptions about the functional form
of the parameter distributions. The use of unbounded distributions, such as the normal distribution, may be regarded as unsuitable
where theory indicates that all are negatively affected by increases in an attribute, such as price. Bounded distributions
such as the triangular and log-normal are unable to model the case where a section of the population is indifferent towards
an attribute, while the remainder are negatively disposed toward it. Train and Sonnier’s bounded mixed logit model accommodates
these features and is employed in this paper. A censored normal and Johnson’s Sb distribution are used to model preferences in the UK for food attributes, including price and GM technology. Bi-modal distributions
are identified regarding GM food: some are unlikely to ever consume it, some are close to indifference and willing to consume
at relatively small discounts while the remainder are fairly unresponsive to further price reductions. 相似文献
Here the authors make two arguments, Japanese industry is characterised by distinctive practices, but these predominate in only certain ‘leading edge’ sectors and were introduced mainly to ensure labour supply. Second, Britain's managers are increasingly outside the internal labour markets of large corporations. In this respect British firms are not becoming ‘Japanese’. 相似文献
The European Union (EU) aspires to be the most competitive, full employment economy in the world and has set a number of ambitious targets to be met by 2010 in order that it can achieve this goal. At the same time, it is pursuing an enlargement policy that will witness the accession of an increasing number of less developed nations. This article explores some of the tensions that exist between these two goals as these are manifest in labour market indicators and finds the likelihood of meeting the deadline set for success remote. 相似文献
We present a model of succession in a firm owned and managed by its founder. The founder decides between hiring a professional manager or leaving management to his heir, as well as on what fraction of the company to float on the stock exchange. We assume that a professional is a better manager than the heir, and describe how the founder's decision is shaped by the legal environment. This theory of separation of ownership from management includes the Anglo‐Saxon and the Continental European patterns of corporate governance as special cases, and generates additional empirical predictions consistent with cross‐country evidence. 相似文献
Background: Non-vitamin K antagonist oral anticoagulants (NOACs) have been included in international guidelines as important alternatives to vitamin K antagonists (VKAs) for the treatment of venous thromboembolism (VTE) and stroke prevention in non-valvular atrial fibrillation (NVAF). Meanwhile, in the Netherlands, NOACs are widely used next to VKAs. The objective of this study is to estimate the cost-effectiveness of treatment with rivaroxaban compared to VKAs in NVAF and VTE patients in the Netherlands, using data from international prospective observational phase IV studies.
Methods: Two models were developed to represent NVAF and VTE patients, populated with patients from the XANTUS (NCT01606995) and XALIA (NCT01619007) international prospective observational studies. The 1-year cost-effectiveness of rivaroxaban use, compared to VKAs, was explored in a population consisting of NVAF and VTE patients (base case) as well as for four scenarios with sub-populations: NVAF patients only, VTE patients only, NVAF patients with unstable international normalized ratio (INR), and NVAF patients using an INR self-measuring device.
Results: In the base case, rivaroxaban saved €72,350 and gained 21 quality-adjusted life-years (QALYs) in a simulation of 2,000 patients over the use of VKAs. Ergo, rivaroxaban was dominant over VKAs. The probabilistic sensitivity analysis showed a probability of 85% for rivaroxaban being dominant and 100% at a willingness-to-pay threshold of €20,000/QALY. Rivaroxaban appeared to be dominant in all scenarios as well, except for the NVAF-patients-only scenario where the incremental cost-effectiveness ratio (ICER) was €157/QALY.
Conclusions: In patients with NVAF or VTE, rivaroxaban treatment is likely to be cost-effective and a potentially cost-saving alternative to VKA in the Netherlands. 相似文献