Author: William T. Dickens Publisher: ISBN: Category : Analysis of variance Languages : en Pages : 48
Book Description
When estimating linear models using grouped data researchers typically weight each observation by the group size. Under the assumption that the regression errors for the underlying micro data have expected values of zero, are independent and are homoscedastic, this procedure produces best linear unbiased estimates. This note argues that for most applications in economics the assumption that errors are independent within groups is inappropriate. Since grouping is commonly done on the basis of common observed characteristics, it is inappropriate to assume that there are no unobserved characteristics in common. If group members have unobserved characteristics in common, individual errors will be correlated. If errors are correlated within groups and group sizes are large then heteroscedasticity may be relatively unimportant and weighting by group size may exacerbate heteroscedasticity rather than eliminate it. Two examples presented here suggest that this may be the effect of weighting in most non-experimental applications. In many situations unweighted ordinary least squares may be a preferred alternative. For those cases where it is not, a maximum likelihood and an asymptotically efficient two-step generalized least squares estimator are proposed. An extension of the two-step estimator for grouped binary data is also presented.
Author: Triplett Jack Publisher: OECD Publishing ISBN: 9264028153 Category : Languages : en Pages : 258
Book Description
Price indexes can be constructed using a “hedonic method” that adjusts for changes in the quality of a product. This handbook sets out best practice for constructing hedonic indexes.
Author: Mick Silver Publisher: International Monetary Fund ISBN: 1451874162 Category : Business & Economics Languages : en Pages : 30
Book Description
The 2005 International Comparison Program's (ICP) estimates of economy-wide purchasing power parity (PPP) are based on parity estimates for 155 basic expenditure headings, mainly estimated using country product dummy (CPD) regressions. The estimates are potentially inefficient and open to omitted variable bias for two reasons. First, they use average prices across outlets as the left-hand-side variable. Second, quality-adjusted prices of non-comparable replacements, required when products in outlets do not match the required specifications, cannot be effectively included. This paper provides an analytical framework based on panel data and hedonic CPD regressions for ameliorating these sources of bias and inefficiency.
Author: Orley Ashenfelter Publisher: Elsevier ISBN: 0080544185 Category : Business & Economics Languages : en Pages : 930
Book Description
Modern labor economics has continued to grow and develop since the first volumes of this Handbook were published. The subject matter of labor economics continues to have at its core an attempt to systematically find empirical analyses that are consistent with a systematic and parsimonious theoretical understanding of the diverse phenomenon that make up the labor market. As before, many of these analyses are provocative and controversial because they are so directly relevant to both public policy and private decision making. In many ways the modern development in the field of labor economics continues to set the standards for the best work in applied economics.This volume of the Handbook has a notable representation of authors - and topics of importance - from throughout the world.
Author: Peter Kennedy Publisher: John Wiley & Sons ISBN: 1405182571 Category : Business & Economics Languages : en Pages : 608
Book Description
Dieses etwas andere Lehrbuch bietet keine vorgefertigten Rezepte und Problemlösungen, sondern eine kritische Diskussion ökonometrischer Modelle und Methoden: voller überraschender Fragen, skeptisch, humorvoll und anwendungsorientiert. Sein Erfolg gibt ihm Recht.
Author: Peter Atkinson Publisher: EOLSS Publications ISBN: 1905839871 Category : Languages : en Pages : 258
Book Description
Geoinformatics is a component of Encyclopedia of Earth and Atmospheric Sciences in the global Encyclopedia of Life Support Systems (EOLSS), which is an integrated compendium of twenty one Encyclopedias. Geoinformatics is a science which develops and uses information science infrastructure to address the problems of geosciences and related branches of engineering. The content of the theme on Geoinformatics is organized with state-of-the-art presentations covering the following aspects of the subject: Sample Data and Survey; Remote Sensing and Environmental Monitoring; Statistical Analysis in the Geosciences; International Cooperation for Data Acquisition and Use, which are then expanded into multiple subtopics, each as a chapter.. These two volumes are aimed at the following five major target audiences: University and College Students Educators, Professional Practitioners, Research Personnel and Policy Analysts, Managers, and Decision Makers and NGOs.
Author: Lauri Mehtatalo Publisher: CRC Press ISBN: 0429530773 Category : Mathematics Languages : en Pages : 560
Book Description
Biometry for Forestry and Environmental Data with Examples in R focuses on statistical methods that are widely applicable in forestry and environmental sciences, but it also includes material that is of wider interest. Features: · Describes the theory and applications of selected statistical methods and illustrates their use and basic concepts through examples with forestry and environmental data in R. · Rigorous but easily accessible presentation of the linear, nonlinear, generalized linear and multivariate models, and their mixed-effects counterparts. Chapters on tree size, tree taper, measurement errors, and forest experiments are also included. · Necessary statistical theory about random variables, estimation and prediction is included. The wide applicability of the linear prediction theory is emphasized. · The hands-on examples with implementations using R make it easier for non-statisticians to understand the concepts and apply the methods with their own data. Lot of additional material is available at www.biombook.org. The book is aimed at students and researchers in forestry and environmental studies, but it will also be of interest to statisticians and researchers in other fields as well.
Author: William T. Dickens
Author: Triplett Jack
Author: Mick Silver
Author: Orley Ashenfelter
Author: Peter Kennedy
Author: Henry S. Shryock
Author: Peter Atkinson 
Author: Owen O. Williams
Author: Lauri Mehtatalo
Author: