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991.
Simplified proofs are given of a standard result that establishes positive semi–definiteness of the difference of the inverses of two non–singular matrices, and of the extension of this result by Milliken and Akdeniz (1977) to the difference of the Moore–Penrose inverse of two singular matrices. 相似文献
992.
993.
A New Approach to Social Assistance: Latin America's Experience with Conditional Cash Transfer Programmes 总被引:1,自引:0,他引:1
Laura B. Rawlings 《International social security review》2005,58(2-3):133-161
Conditional cash transfers are a departure from more traditional approaches to social assistance that represents an innovative and increasingly popular channel for the delivery of social services. Conditional cash transfers provide money to poor families contingent upon certain behaviour, usually investments in human capital such as sending children to school or bringing them to health centres on a regular basis. They seek both to address traditional short-term income support objectives and promote the longer-term accumulation of human capital by serving as a demand-side complement to the supply of health and education services. Evaluation results reveal that this innovative design has been quite successful in addressing many of the failures in delivering social assistance such as poor poverty targeting, disincentive effects and limited welfare impacts. There is clear evidence of success from the first generation of programmes in Brazil, Colombia, Mexico and Nicaragua in increasing enrolment rates, improving preventive healthcare and raising household consumption. Despite this promising evidence, many questions remain unanswered about conditional cash transfer programmes, including the replicability of their success under different 相似文献
994.
Two independent random samples are drawn from two multivariate normal populations with mean vectors μ1 and μ2 and a common
variance-covariance matrix Σ. Ahmed and Saleh (1990) considered preliminary test maximum likelihood estimator (PMLTE) for estimating μ1 based on the Hotelling's T
N
2, when it is suspected that μ1=μ2. In this paper, the PTMLE based on the Wald (W), Likelihood Ratio (LR) and Lagrangian Multiplier (LM) tests are considered. Using the quadratic risk function, the conditions of superiority of the proposed estimator for departure
parameter are derived. A max-min rule for the size of the preliminary test of significance is presented. It is demonstrated
that the PTMLE based on W test produces the highest minimum guaranteed efficiencies compared to UMLE among the three test procedures. 相似文献
995.
In the present paper, we introduce and study Renyi's information measure (entropy) for residual lifetime distributions. It
is shown that the proposed measure uniquely determines the distribution. We present characterizations for some lifetime models.
Further, we define two new classes of life distributions based on this measure. Various properties of these classes are also
given. 相似文献
996.
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
997.
B. L. S. Prakasa Rao 《统计学通讯:理论与方法》2018,47(18):4415-4421
We discuss some analogues of the lack of memory property, the strong lack of memory property and the almost lack of memory properties for the Gompertz distribution as applications of the integrated Cauchy functional equation. 相似文献
998.
A likelihood approach is considered for the problems of estimating the changepoint and other parameters in a multivariable two-phase regression.Methods for finding the maximum likelihood estimates are given for the cases when the covariance matrix is known, and unknown.The distribution of the usual likelihood ratio test statistic is Investigated using simulations, and a Monte-Carlo aporoach is suggested for testing for the existence of a change-point.Numerical1 Illistrute aie provided. 相似文献
999.
The exact distributions of the estimated process capability indices are presented and their means, variances, and mean-squared errors are given. The basic assumption is that the process measurements are taken from a normal distribution. Theresults in this article are useful in evaluating process capability. 相似文献
1000.
B. L. Agarwal 《统计学通讯:理论与方法》2013,42(2):723-738
In the present paper, the author has considered and compared the power of three test procedures, based on two preliminary tests of significance (PTS), for testing a main effect in a three factor factorial experiment. Davenport and Webster (1973) type test statistics are used in the final test. Recommendation for a suitable size of PTS has been made so that the power of a test procedure is adequately high. 相似文献