Proxy (statistics)

About: Proxy (statistics) is a research topic. Over the lifetime, 5257 publications have been published within this topic receiving 94504 citations. The topic is also known as: proxy variable & proxy measurement.

Proxy signatures, Revisited

Abstract: Proxy signatures, introduced by Mambo, Usuda and Okamoto allow a designated person to sign on behalf of an original signer. This paper first presents two new types of digital proxy signatures called partial delegation with warrant and threshold delegation. Proxy signatures for partial delegation with warrant combines the benefit of Mambo's partial delegation and Neuman's delegation by warrant, and then in threshold delegation the proxy signer's power to sign messages is shared. Moreover, we also propose straightforward and concrete proxy signature schemes satisfying our conditions.

Taxonomic bias in conservation research.

Abstract: Taxonomic bias is pervasive in organismal research; i.e., research is not proportional to organisms' frequency in nature ([1][1]–[4][2]). Quantifying research bias is difficult, but a reasonable proxy measure is to evaluate subject organisms in the research literature (e.g., [1][1], [4][2]). For

Estimating the Returns to College Quality with Multiple Proxies for Quality

Abstract: Existing studies of the effects of college quality on wages typically rely on a single proxy variable for college quality. This study questions the wisdom of using a single proxy given that it likely contains substantial measurement error. We consider four econometric approaches to the problem that involve the use of multiple proxies for college quality: factor analysis, instruments variables, a method recently proposed by Lubotsky and Wittenberg, and a GMM estimator. Our estimates suggest that the existing literature understates the wage effects of college quality and illustrate the value of using multiple proxies in this and other similar contexts.

On the Cross-sectional Relation between Expected Returns and Betas

Abstract: There is an exact linear relation between expected returns and true "betas" when the market portfolio is on the ex ante mean-variance efficient frontier, but empirical research has found little relation between sample mean returns and estimated betas. A possible explanation is that market portfolio proxies are mean-variance inefficient. We categorize proxies that produce particular relations between expected returns and true betas. For the special case of a zero relation, a market portfolio proxy must lie inside the efficient frontier, but it may be close to the frontier. CONTRARY TO THE PREDICTIONS of the Sharpe, Lintner, and Black Capital Asset Pricing Model (hereafter the SLB CAPM or SLB Model; see Sharpe (1964), Lintner (1965), and Black (1972)), a decade of empirical studies has reported little evidence of a significant cross-sectional relation between average returns and betas. Yet it is well known (Roll (1977), Ross (1977)) that a positive and exact cross-sectional relation between ex ante expected returns and betas must hold if the market index against which betas are computed lies on the positively sloped segment of the mean-variance efficient frontier. Not finding a positive cross-sectional relation suggests that the index proxies used in empirical testing are not ex ante mean-variance efficient. Some of the empirical studies have uncovered variables other than beta that have power in explaining the sample cross-sectional variation in mean returns. But the true cross-sectional expected return-beta relation is exact when the index is efficient, so no variable other than beta can explain any part of the true cross-section of expected returns. Conversely, if the index is not efficient, the ex ante cross-sectional relation does not hold exactly and other variables can have explanatory power. Indeed, any variable that happens to be cross-sectionally related to expected returns could have discernible empirical power when the index proxy is ex ante inefficient. Again, the empirical evidence supports an inference that market index proxies used in testing are not on the ex ante efflcient frontier. But the puzzle in the empirical work is not so much that the cross-sectional mean return-beta relation is imperfect nor that other variables have empiri

Proxy-based authorization and accounting for distributed systems

Abstract: A unified model is presented for authentication, authorization, and accounting that is based on proxies. It is shown that the proxy model for authorization can be used to support a wide range of authorization and accounting mechanisms. The proxy model strikes a balance between access-control-list anti capability-based mechanisms, allowing each to be used where appropriate and allowing their use in combination. The author describes how restricted proxies can be supported using existing authentication methods. >