36 research outputs found
Seeing Is Believing: Mathematics Visualization In Economics Education
Visualization through the use of physical objects is an important method that instructors can use to convey and solidify an understanding of economic principles in their novice students of economics. This paper outlines three simple examples which have been successful in the classroom, each taking a question that students frequently ask --- why we build models, what a model looks like, and what we learn from a model --- and answering them with images of airplanes, watermelons and windows
Forced Out of the Closet: The Impact of the American Inventors Protection Act on the Timing of Patent Disclosure
Beginning in November 2000, patent applications filed in the United States are disclosed after 18 months, rather than when the patent is granted. Using U.S. patent data from 1976-1996, we find that major inventions are most likely to be affected, as they take longer to go through the application process. We provide evidence that this change will result in faster knowledge diffusion, and conclude with a simulation of the law's potential effect on patent grants.
Fitting the integrated Spectral Energy Distributions of Galaxies
Fitting the spectral energy distributions (SEDs) of galaxies is an almost
universally used technique that has matured significantly in the last decade.
Model predictions and fitting procedures have improved significantly over this
time, attempting to keep up with the vastly increased volume and quality of
available data. We review here the field of SED fitting, describing the
modelling of ultraviolet to infrared galaxy SEDs, the creation of
multiwavelength data sets, and the methods used to fit model SEDs to observed
galaxy data sets. We touch upon the achievements and challenges in the major
ingredients of SED fitting, with a special emphasis on describing the interplay
between the quality of the available data, the quality of the available models,
and the best fitting technique to use in order to obtain a realistic
measurement as well as realistic uncertainties. We conclude that SED fitting
can be used effectively to derive a range of physical properties of galaxies,
such as redshift, stellar masses, star formation rates, dust masses, and
metallicities, with care taken not to over-interpret the available data. Yet
there still exist many issues such as estimating the age of the oldest stars in
a galaxy, finer details ofdust properties and dust-star geometry, and the
influences of poorly understood, luminous stellar types and phases. The
challenge for the coming years will be to improve both the models and the
observational data sets to resolve these uncertainties. The present review will
be made available on an interactive, moderated web page (sedfitting.org), where
the community can access and change the text. The intention is to expand the
text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics &
Space Scienc
Novel genetic loci associated with hippocampal volume
The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness
The OECD Technology Concordance (OTC): Patents by Industry of Manufacture and Sector of Use
While patent data are now readily available for most nations, these data are still of minimal use for economic analysis due to their mode of presentation. Patents are recorded for administrative purposes using the International Patent Classification (IPC) system, which categorises inventions by product or process. Instead, most economic researchers and analysts are interested in the particular sectors of the economy responsible for the invention or its subsequent use. The OECD Technology Concordance (OTC) presented here, like its predecessor the Yale Technology Concordance, is a tool that bridges definitions, allowing researchers to transform IPC-based patent data into patent counts by sector of the economy. This paper presents the methodology, some sample output and empirical tests of the method. It should be noted that the methodological work on the distribution of patent data by industry at the OECD is an early stage and further improvement of the OTC is expected in the ... Il est facile aujourdâhui de se procurer des donnĂ©es sur les brevets dans la plupart des pays, mais leur mode de prĂ©sentation leur enlĂšve presque toute pertinence pour lâanalyse Ă©conomique. Les brevets sont enregistrĂ©s Ă des fins administratives selon le systĂšme de Classification internationale des brevets (CIB), dans lequel les inventions sont regroupĂ©es par produits ou procĂ©dĂ©s. Par contre, la plupart des donnĂ©es et des analyses Ă©conomiques portent sur les secteurs de lâĂ©conomie Ă lâorigine dâune invention ou sur ceux qui en sont les utilisateurs. A lâinstar du Technology Concordance de Yale en usage avant lui, le Technology Concordance de lâOCDE (OTC) prĂ©sentĂ© ici est un outil qui Ă©tablit un lien entre les deux logiques et permet aux chercheurs, Ă partir des donnĂ©es sur les brevets classĂ©es selon le systĂšme CIB, de rĂ©pertorier les brevets par secteur Ă©conomique. On trouvera dans le prĂ©sent document, la mĂ©thodologie, quelques exemples dâapplication, et des essais empiriques de la ...
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Paying for Green: An economics literature review on the constraints to financing environmental innovation
In an effort to explore the potential for financing environmental innovation, this paper examines different forms of financing and attempts to evaluate their effectiveness. The study considers both public and private forms of funding as well as providing policy suggestions for the support of appropriate financing for eco-innovation