1,721,004 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ambiguity Aversion and Cost-Plus Procurement Contracts
Full text linkThis paper presents a positive theory about the contractual form of procurement contracts under cost uncertainty. While the cost of manufacture is uncertain it can be controlled, to an extent depending on the effort exerted by the agent. The effort exerted by the agent is not contractible but causes disutility to the agent. Hence, the amount of effort exerted depends on the power of incentives built into the terms of reimbursement agreed to in the contract. The analysis in the paper explicitly models the possibility that the belief about the cost uncertainty is ambiguous, in the sense that belief is described by a set of probabilities, rather than by a single probability. This allows us to incorporate ambiguity aversion (behavior of the kind seen in Ellsberg`s "paradox") into the players` objective functions. The paper finds that, provided the agent is more averse to ambiguity than the principal, the more the ambiguity of belief the lower the power of the optimal incentive scheme. The fix-price contract is optimal if there is no ambiguity, but if the ambiguity is high enough a cost-plus contract is optimal; in between, a cost-share scheme is optimal. It is contended that the finding is particularly useful in explaining facts about the wide use of cost-plus and similar low powered contracts in research and development (R&D) procurement by the U.S. Department of Defense.Procurement contracts, Incentive contracts, Uncertainty aversion, Ellsberg`s paradox, Cost reimbursement contracts, Cost-plus contracts, Fixed price contracts
Foundations of ambiguity and economic modeling
No full textAre foundations of models of ambiguity-sensitive preferences too flawed to be usefully applied to economic models?� Al-Najjar and Weinstein (2009) say such is indeed the case.� In this paper, first, we point out that many of the key arguments by Al-Najjar and Weinstein do not apply to quite a few of the ambiguity preference models of more recent vintage, and therefore to that extent do not undermine the foundational aspects or applicability of ambiguity models in general.� Second, we argue the focus in that paper on Ellsberg examples is an overly narrow concern; the Ellsberg examples have their uses but they are not the best context to understand why reasonable real-world agents may find acting with ambiguity-sensitive preferences normatively or prescriptively appealing.� Finally, normative considerations aside, we submit that Al-Najjar and Weinstein are unduly dismissive of the power of such preferences to provide illuminating positive analyses of economic phenomena.Ambiguity, Uncertainty, Knightian uncertainty, Ambiguity aversion, Uncertainty aversion, Ellsberg paradox, Dynamic decision making, Dynamic programming under ambiguity, Smooth ambiguity, Consequentialism, Sunk cost fallacy, Multiple priors, Rationaltiy
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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