Consider N independent stochastic processes \((X_i(t), t\in [0,T])\), \(i=1,\ldots , N\), defined by a stochastic differential equation with random effects where the drift term depends linearly on a random vector \(\Phi _i\) and the diffusion coefficient depends on another linear random effect \(\Psi _i\). For these effects, we consider a joint parametric distribution. We propose and study two approximate likelihoods for estimating the parameters of this joint distribution based on discrete observations of the processes on a fixed time interval. Consistent and \(\sqrt{N}\)-asymptotically Gaussian estimators are obtained when both the number of individuals and the number of observations per individual tend to infinity. The estimation methods are investigated on simulated data and show good performances. 相似文献
ABSTRACTThis paper investigates the added value of an organic ingredient strategy and the transfer mechanisms at work when placing an organic label on product brands. We proposed and empirically tested an integrated model that included three stages: brand and label equity; transfer mechanisms; and product evaluation. We first selected an organic label and product brands and then tested our hypotheses with a sample of French consumers. The results confirm the positive influence of brand and label equity on transfer mechanisms (brand/label perceived fit and ease of transfer) and, in turn, illustrate how ease of transfer influences the overall product evaluation. A surprising result is that brand/label perceived fit does not directly affect the overall product evaluation; rather, it only influences brand/label ease of transfer. 相似文献
There is some concern that the unobserved preference heterogeneity in random utility maximization theory-based discrete choice experiment modelling is an important source of error variability. The randomness in utility is often interpreted as interpersonal preference heterogeneity but it can also be intrapersonal random variation in preferences. We compare utility maximization and regret minimization-based choice models’ sensitivity to individual heterogeneity, examine differences between two consecrated models and validate with empirical illustrations. We use frequency of category (public, semi-private, and private) of bed chosen from Swiss cross-sectional datasets (2007–2012) to compare two approaches – utility maximization and regret minimization by applying multinomial logit (MNL) models in regard to the variances in utility (regret) function, goodness-of-fit and predicted marginal effects (pseudo-elasticity) of additional payment. We find parameters with the same sign and estimates with almost same order of magnitude in both the approaches. The statistical significance of attribute effects is consistent in all variants of utility -based MNL models while effects of different attributes are significant only in heteroskedastic extreme value (HEV) variant of regret-based MNL models. This empirical illustration suggests that HEV variant of regret-based models perform better in capturing attribute effects in choice behaviour. 相似文献
ABSTRACTBy calling the present condition of the French food retail industry an interregnum, this research considers the impact of liquid modernity on this sector and looks for signs of a new order at a designing stage. Nine experts representing large retailers and entrepreneurs using alternative modes of food retailing were interviewed. An interpretive analysis reveals a wide diversity of changes. Following Bauman’s liquid metaphor, we identify shock, transformations, and crisis in food retailing, which we describe as phases that mark the dynamics in the shift from solid to liquid retailing. We discuss how retailers are adapting and deploying tactics both to respond and belong to these liquid times and how retailers can regain some legitimacy by claiming a role in territorial sovereignty. 相似文献
Asenapine is the first tetracyclic antipsychotic approved in Canada for the treatment of schizophrenia (SCZ). Asenapine has shown a comparable efficacy profile to other atypical antipsychotics and it is associated with a favourable metabolic profile and less weight gain. This study aimed to assess the economic impact of asenapine compared to other atypical antipsychotics in the treatment of SCZ in Canada.
Methods:
A decision tree combined with a Markov model was constructed to assess the cost-utility of asenapine compared with other atypical antipsychotics. The decision tree takes into account the occurrence of extrapyramidal symptoms, the probability of switching to a different antipsychotic, and the probability of gaining weight. The Markov model takes into account long-term metabolic complications including diabetes, hypertension, coronary heart diseases, and stroke. In the base-case analysis, asenapine was compared to olanzapine. Asenapine was also compared with other atypical antipsychotics commonly used in Canada in alternative scenarios. Analyses were conducted from both Canadian Ministry of Health (MoH) and societal perspectives over a 5-year time horizon.
Results:
In the treatment of SCZ, asenapine is a dominant strategy over olanzapine from both MoH and societal perspectives. Compared to quetiapine, asenapine is also a dominant strategy. Furthermore, asenapine has a favorable economic impact compared to ziprasidone and aripiprazole, as these antipsychotics are not cost-effective compared to asenapine from both MoH and societal perspectives.
Conclusion:
Despite the short time horizon, the lack of compliance data and the assumptions made, this economic evaluation demonstrates that asenapine is a cost-effective strategy compared to olanzapine and to most of the atypical antipsychotics frequently used in Canada. 相似文献