1,721,037 research outputs found
Replication data for: Regulation and Capacity Competition in Health Care: Evidence from Dialysis Markets
No full textDai, Mian, and Tang, Xun, (2015) "Regulation and Capacity Competition in Health Care: Evidence from Dialysis Markets." Review of Economics and Statistics 97:5, 965-982
Crime Hotspot Detection: A Computational Perspective
No full textGiven a set of crime locations, a statistically significant crime hotspot is an area where the concentration of crimes inside is significantly higher than outside. The motivation of crime hotspot detection is twofold: detecting crime hotspots to focus the deployment of police enforcement and predicting the potential residence of a serial criminal. Crime hotspot detection is computationally challenging due to the difficulty of enumerating all potential hotspot areas, selecting an interest measure to compare these with the overall crime intensity, and testing for statistical significance to reduce chance patterns. This chapter focuses on statistical significant crime hotspots. First, the foundations of spatial scan statistics and its applications (i.e. SaTScan) to circular hotspot detection are reviewed. Next, ring-shaped hotspot detection is introduced. Third, linear hotspot detection is described since most crimes occur along a road network. The chapter concludes with future research directions in crime hotspot detection.Eftelioglu, Emre; Tang, Xun; Shekhar, Shashi. (2016). Crime Hotspot Detection: A Computational Perspective. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/215995
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
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
You Can’t Smoke Here: Towards Support for Space Usage Rules in Location-aware Technologies
No full textRecent work has identified the lack of space usage rule (SUR) data – e.g. “no smoking”, “no campfires” – as an important limitation of online/mobile maps that presents risks to user safety and the environment. In order to address this limitation, a large-scale means of mapping SURs must be developed. In this paper, we introduce and motivate the problem of mapping space usage rules and take the first steps towards identifying solutions. We show how computer vision can be employed to identify SUR indicators in the environment (e.g. “No Smoking” signs) with reasonable accuracy and describe techniques that can assign each rule to the appropriate geographic feature. We also discuss how our methods can be applied to large repositories of spatially-referenced images (e.g. Google Street View) to generate global-scale datasets of SURs.Samsonov, Pavel; Tang, Xun; Schoening, Johannes; Kuhn, Werner. (2014). You Can’t Smoke Here: Towards Support for Space Usage Rules in Location-aware Technologies. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/215959
Essays on Discrete Choice Demand Estimation and Spatial Analysis
No full textThis dissertation thesis contains three chapters in the fields of empirical industrial organization and applied econometrics. In my first chapter, I combine complementarity in bundle choice and consideration set of products into a demand model for differentiated products. I explore the identification when the market shares of products, not bundles are observed, and use a novel estimation approach via combining the loglikelihood of consumer choices and market shares with moment conditions. I apply the model to the yogurt market with consumer-level and store-level data. I find a considerable demand synergy in the bundle of different products and a significant proportion of consumer inertia, defined here as choosing from the last purchases, in consumer demand for yogurt. Compared to the standard discrete choice model, my estimation results suggest that accounting for complementarity between products and consumers’ limited consideration set can substantially affect price competition analysis.
The second chapter is a collaborated work on the application of spatial econometrics in banking industry. We examine the direct and indirect impacts of natural disasters on deposit rates of bank branches during the 2008 – 2017 period. We find that spatial spillover effects substantially explain the total impact for deposit rate-setting branches. Our analysis and findings contribute to the existing literature by showing that the responses of branches to natural disasters are not confined only to those branches in counties directly affected but to branches in neighboring counties through competitive effects. Our results also confirm that spillover effects occur among branches across counties via a social connection and geographical network.
The third chapter is on the identification and inference of a discrete choice model with partially unobserved attributes. It is motivated by the observation that consumers often do not account for unplanned purchases in their store choice when planning grocery trips. I show that the model is partially identified, and the sharp identified set is characterized via both moment-based inequalities and likelihood-based criteria. Using household grocery shopping data, I show that point estimation from the standard multinomial choice model assuming no unplanned purchases is rejected
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