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1.
Generally, the semiclosed-form option pricing formula for complex financial models depends on unobservable factors such as stochastic volatility and jump intensity. A popular practice is to use an estimate of these latent factors to compute the option price. However, in many situations this plug-and-play approximation does not yield the appropriate price. This article examines this bias and quantifies its impacts. We decompose the bias into terms that are related to the bias on the unobservable factors and to the precision of their point estimators. The approximated price is found to be highly biased when only the history of the stock price is used to recover the latent states. This bias is corrected when option prices are added to the sample used to recover the states' best estimate. We also show numerically that such a bias is propagated on calibrated parameters, leading to erroneous values. The Canadian Journal of Statistics 48: 8–35; 2020 © 2019 Statistical Society of Canada  相似文献   
2.
Explicitly aimed at understanding and controlling molecular and cellular processes at the root of senescence and biological aging, regenerative medicine aspires to artificially reproduce the biological processes that enable the body to regenerate itself. This no longer involves conserving the body's state of balance by combating disease, as in clinical medicine, but rather fighting degeneration itself. From stem cell research to gene therapy to the production of replacement tissues, regenerative medicine perfectly corresponds to the logic of biomedicalization specific to postmodern society. Based on a series of 18 interviews conducted with Canadian researchers and clinicians in the field of regenerative medicine, this article seeks to understand representations of the aging body among researchers in this field. Seen from a strictly negative angle, aging is assimilated by researchers to an inevitable catastrophe that nevertheless must be combated. More closely observing the theoretical model of regenerative biology and the types of treatments developed, it can be observed, however, that this medicine of the future does not target the elderly, but rather promises youth the ability to regenerate themselves to avoid aging.  相似文献   
3.
The conditional tail expectation (CTE) is an indicator of tail behavior that takes into account both the frequency and magnitude of a tail event. However, the asymptotic normality of its empirical estimator requires that the underlying distribution possess a finite variance; this can be a strong restriction in actuarial and financial applications. A valuable alternative is the median shortfall (MS), although it only gives information about the frequency of a tail event. We construct a class of tail Lp-medians encompassing the MS and CTE. For p in (1,2), a tail Lp-median depends on both the frequency and magnitude of tail events, and its empirical estimator is, within the range of the data, asymptotically normal under a condition weaker than a finite variance. We extrapolate this estimator and another technique to extreme levels using the heavy-tailed framework. The estimators are showcased on a simulation study and on real fire insurance data.  相似文献   
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This paper seeks to demonstrate the major benefits that a dedicated policy of co–development can bring to three major actors affected by immigration: receiving states, countries of origin, and the immigrants themselves. True co–development involves sustained cooperation between receiving nations and source nations in the management of both legal and illegal migratory flows. At the same time, it fosters the economic and demographic development of both the sending and the receiving country. This cooperation is based in large measure on understanding that, more than ever before, the best migration policy for developed nations is one that seeks not to block, but to smoothly regulate the circulation and re–circulation of the majority of foreigners and immigrants. As a result, Northern countries will be able to concentrate the state’s limited control resources on selected targets such as criminals, delinquents, and migrants arrested multiple times for unauthorized entry or residence. Developed nations must recognize that the vast majority of immigrants wish to retain close links to their country of origin, and with drastically improved transportation and communication links, most migrants are increasingly able to do so. Northern states should adapt policies that, for the most part, accommodate immigrants’ wishes to maintain active ties to their homeland. Such measures are generally in the best interests of the receiving countries, source countries, and of course, the immigrants themselves. The various problems faced by these three main actors regarding migration as they seek to pursue activities in their best interest is considered, followed by the advantages that a policy of co–development has for these actors: for receiving nations in terms of meeting labour force needs, reducing demographic problems, and controlling illegal immigration; and for source countries in terms of increased access to visas, increased amounts and efficacy of remittances, and the return and re–circulation of skilled and seasonal workers, and retirees. The interests of the immigrants themselves will be considered at various points throughout the discussion, in the context of the effects that the various policies of receiving and sending countries will have on them.  相似文献   
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Using data from a national survey of pharmacists who are members of the American Pharmaceutical Association, we examine the union voting intentions of employee pharmacists. We find that union instrumentality regarding professionalism is a primary predictor of union voting intent among these employees. In addition, this predictor mediates the relationship between the level of professionalism at a pharmacist’s current employment situation and his or her expected union vote. Also important to union voting intent are respondent beliefs about union instrumentality regarding pecuniary issues, prior union experience, as well as overall job satisfaction. Implications for employers, unions, and researchers are drawn. We thank Mary Graham, Jann Skelton, Paul Swiercz, Terry Thomason, and participants at the Seventh Bar-gaining Group Conference at Michigan State University for their comments on earlier versions of this paper. This research was made possible by a grant from the American Pharmaceutical Association.  相似文献   
8.
The sociocultural content of foreign language textbooks has become a concern of scholars and practitioners owing to the fact that the traditional emphasis on purely linguistic issues has been expanded to embrace a language in context approach. This paper studies the English‐speaking communities that are described in English language teaching textbooks marketed in Spain. It examines to what extent an international and/or intercultural approach is a constituent element in their design.  相似文献   
9.
A Continuous Sampling Plan, CSP-CUSUM, is proposed based on the use of Cumulative Sums (CUSUMs) for deciding when to switch between the phases of sampling inspection and 100% inspection. The Geometric CUSUM, also termed the Run-length CUSUM, is chosen for this purpose, and two separate CUSUMs are to be operated, one for each inspection phase. The conventional measures of performance for CSPs such as average outgoing quality, average fraction inspected, and average proportion passed under sampling inspection are evaluated for CSP-CUSUM, and comparisons with some standard CSPs are presented. An additional performance-measure, Average Cycle Length, is proposed. A table is provided to aid the choice of parameters for the operation of CSP-CUSUM. It is recommended that a Geometric CUSUM control chart be maintained in parallel with CSP-CUSUM to detect significant upward shifts in the incoming fraction defective.  相似文献   
10.
Conservation biology aims at assessing the status of a population, based on information which is often incomplete. Integrated population modelling based on state‐space models appears to be a powerful and relevant way of combining into a single likelihood several types of information such as capture‐recapture data and population surveys. In this paper, the authors describe the principles of integrated population modelling and they evaluate its performance for conservation biology based on a case study, that of the black‐footed albatross, a northern Pacific albatross species suspected to be impacted by longline fishing  相似文献   
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