Category Reporting in Charitable Giving: An Experimental Analysis

Harbaugh (1998a) has shown theoretically that charities can increase the size of donations by publicly acknowledging their donors using categories. In a complementary paper,using the data on the donations given by 146 lawyers to their almamater law school, Harbaugh (1998b) provided empirical support for this theoretical assertion. Essentially, being acknowledged in categories gives donors some prestige benefits. In this paper, we experimentally investigate the impact of various reporting plans as described in Harbaugh (1998a and 1998b) on the behavior of donors. Our results show that, although the category reporting plan has no significant impact on the size of donations when compared to the exact reporting plan and the no reporting plan, it does signi�ficantly alter the charitable behavior of donors. We show that the presence of a category reporting plan induces the clustering of donations on the lower boundaries of categories, which suggests that donors are motivated by prestige. We also discover that in some circumstances the presence of prestige benefi�ts crowds out the warm glow motive for giving

Categories of holomorphic line bundles on higher dimensional noncommutative complex tori

We construct explicitly noncommutative deformations of categories of holomorphic line bundles over higher dimensional tori. Our basic tools are Heisenberg modules over noncommutative tori and complex/holomorphic structures on them introduced by A. Schwarz. We obtain differential graded (DG) categories as full subcategories of curved DG categories of Heisenberg modules over the complex noncommutative tori. Also, we present the explicit composition formula of morphisms, which in fact depends on the noncommutativity.Comment: 28 page

Mapping carbon nanotube orientation by fast fourier transform of scanning electron micrographs

A novel method of applying a two-dimensional Fourier transform (2D-FFT) to SEM was developed to map the CNT orientation in pre-formed arrays. Local 2D-FFTs were integrated azimuthally to determine an orientation distribution function and the associated Herman parameter. This approach provides data rapidly and over a wide range of lengthscales. Although likely to be applicable to a wide range of anisotropic nanoscale structures, the method was specifically developed to study CNT veils, a system in which orientation critically controls mechanical properties. Using this system as a model, key parameters for the 2D-FFT analysis were optimised, including magnification and domain size; a model set of CNT veils were pre-strained to 5%, 10% and 15%, to vary the alignment degree. The algorithm confirmed a narrower orientation distribution function and increasing Herman parameter, with increasing pre-strain. To validate the algorithm, the local orientation was compared to that derived from a common polarised Raman spectroscopy. Orientation maps of the Herman parameter, derived by both methods, showed good agreement. Quantitatively, the mean Herman parameter calculated using the polarised Raman spectroscopy was 0.42 ± 0.004 compared to 0.32 ± 0.002 for the 2D-FFT method, with a correlation coefficient of 0.73. Possible reasons for the modest and systematic discrepancy were discussed

Can market-clearing models explain U.S. labor market fluctuations?

Throughout the past two decades, market-clearing models of the business cycle have been praised for their ability to explain key empirical features of the post-war U.S. business cycle. Real business cycle (RBC) theory shows that in a model grounded in microeconomic foundations, disturbances to national productivity can explain how aggregate variables such as GDP, consumption and investment behave over time, relative to each other. One of the primary weaknesses of the standard RBC model, however, is its inability to account for some important aspects of U.S. labor market fluctuations. In this article, Victor E. Li summarizes important U.S. business cycle facts and examines how and why these market-clearing models have so much difficulty explaining the mannner in which these facts pertain to the labor market. Li then develops a simple market-clearing framework that demonstrates how a more realistic treatment of unemployment and incomplete risk-sharing may provide an alternative approach to better account for these labor market facts. In particular, Li looks at the situation where the risk of being unemployed cannot be completely shared across all individuals when there are unexpected aggregate economic shocks.Business cycles ; Labor market ; Econometric models