How Has the Literature on Gini's Index Evolved in the Past 80 Years?

The Gini coefficient or index is perhaps one of the most used indicators of social and economic conditions. From its first proposal in English in 1921 to the present, a large number of papers on the Gini index has been written and published. Going through these papers represents a demanding task. The aim of this survey paper is to help the reader to navigate through the major developments of the literature and to incorporate recent theoretical research results with a particular focus on different formulations and interpretations of the Gini index, its social welfare implication, and source and subgroup decomposition.Gini coefficent or index; social welfare; decomposition; computation

How Should We Measure Global Poverty in a Changing World?

development, poverty, measurement, China, rural, urban

Micro Foundations of Price-Setting Behaviour: Evidence from Canadian Firms

How do firms adjust prices in the marketplace? Do they tend to adjust prices infrequently in response to changes in market conditions? If so, why? These remain key questions in macroeconomics, particularly for central banks that work to keep inflation low and stable. The authors use the Bank of Canada's 2002-03 price-setting survey data to investigate Canadian firms' price-setting behaviour; they also analyze the micro foundations for the firms' pricing behaviour using count data and probit models. The authors find that, all else being equal, firms tend to adjust prices more frequently if they are state-dependent price-setters, operate in the trade sector, or have large variable costs or more direct competitors. There are various sticky-price theories; in the Bank's price-setting survey, the senior management of firms were read a simple statement in non-technical language that paraphrased each sticky-price theory, and were then asked whether the statement applied to their firm. The most frequently recognized sticky-price theories are customer relations, cost-based pricing, and coordination failure. The authors' analysis indicates that if firms recognize coordination failure on price increases, sticky information, menu costs, factor stability, or customer relations as being important, they tend to adjust prices less frequently. The authors also find that the patterns discernible within firms' recognition of stickyprice theories are strongly associated with firms' micro foundations.Inflation and prices; Transmission of monetary policy

The Growth of Poor Children in China 1991-2000: Why Food Subsidies May Matter

height-for-age; child heath; growth; inequality; poverty; food subsidies; China

The Impact of Hedging on Stock Return and Firm Value: New Evidence from Canadian Oil and Gas Companies

This paper analyzes the impact of hedging activities of large Canadian oil and gas companies on their stock returns and firm value. Differing from the existing literature this research finds that some of these relationships are nonlinear based on the framework of nonlinear generalized additive models. The research based on this more general methodology reveals some interesting findings on oil and gas hedging activities. The large Canadian oil and gas firms are able to use hedging to protect downside risk against the unfavorable oil and gas price changes. But oil hedging appears to be more effective in protecting stock returns than gas hedging is when downside risk presents. In addition, oil and gas reserves are more likely to play a positive (negative) role when the oil and gas prices are increasing (decreasing). Finally, hedging, in particular hedging on gas, together with profitability, investment and leverage, has certain impacts on firm value.oil; gas; hedging; return; firm value; general additive models ; Canada

Computational methods for two-phase flow with soluble surfactant

A mathematical model is formulated and solved for the two-phase flow of a viscous drop or inviscid bubble in an immiscible, viscous surrounding fluid in the zero Reynold\u27s number or Stokes flow limit. A surfactant that is present on the interface is also soluble in the exterior fluid, and the drop is deformed by an imposed linear flow. The geometry is two-dimensional and Cartesian. The dissolved surfactant is considered in the physically realistic limit of large bulk Péclet number. That is, it convects and diffuses as a passive scalar in the bulk flow where the ratio of its convection to diffusion is large. The large bulk Péclet number limit presents a significant challenge for traditional numerical methods, since it implies that large gradients of bulk surfactant concentration can develop in a spatially narrow boundary or transition layer adjacent to the drop interface. The layer structure needs to be resolved accurately so that the bulk-interface surfactant exchange, surface surfactant concentration, and interfacial surface tension can be evaluated to determine the drop\u27s dynamics and evolution. To resolve this computational difficulty, the dynamics of the transition layer are modeled by a leading order singular perturbation reduction of the conservation law for dissolved surfactant that is derived in the large bulk Péclet number limit. Two versions of the boundary integral equation for two-phase Stokes flow are presented and used as an underlying fluid solver in the absence of surfactant effects. To evaluate the influence of soluble surfactant the boundary integral solver is coupled to the evolution of surface surfactant concentration and the transition layer equation. The transition layer equation is first solved by a mesh-based numerical method that has a spectrally accurate equal arc length frame for discretization of the interface and a second order time-step. Results of numerical simulations are presented for a range of different physical parameters. An analytical solution of the transition layer equation by a Green\u27s function representation is also derived, which leads to a second, mesh-free algorithm. Numerical results of the mesh-based and mesh-free methods are compared

Energy levels of a parabolically confined quantum dot in the presence of spin-orbit interaction

We present a theoretical study of the energy levels in a parabolically confined quantum dot in the presence of the Rashba spin-orbit interaction (SOI). The features of some low-lying states in various strengths of the SOI are examined at finite magnetic fields. The presence of a magnetic field enhances the possibility of the spin polarization and the SOI leads to different energy dependence on magnetic fields applied. Furthermore, in high magnetic fields, the spectra of low-lying states show basic features of Fock-Darwin levels as well as Landau levels.Comment: 6 pages, 4 figures, accepted by J. Appl. Phy

Variations of Cloud and Radiative Properties of Boundary-layer and Deep Convective Systems with Sea Surface Temperature Anomalies

Gridded monthly-mean satellite data contain compositing information from different cloud system types and clear-sky environments. To isolate the variations of cloud physical properties of an individual cloud system type with its environment, orbital data are needed. In this study, we will analyze the variations of cloud and radiative properties of boundary-layer clouds and deep convective cloud systems with sea surface temperature (SST) anomalies. We use Terra-CERES (Clouds and the Earth s Radiant Energy System) Level 2 data to classify distinct cloud objects defined by cloud-system types (deep convection, boundary-layer cumulus, stratocumulus and overcast clouds), sizes, geographic locations, and matched large-scale environments. This analysis method identifies a cloud object as a contiguous region of the Earth with a single dominant cloud-system type. It determines the shape and size of the cloud object from the satellite data and the cloud-system selection criteria. The statistical properties of the identified cloud objects are analyzed in terms of probability density functions (PDFs) of a single property or joint PDFs between two properties. The SST anomalies are defined as the differences from five-year annual-cycle means. Individual cloud objects are sorted into one of five equal size subsets, with the matched SST anomalies ranging from the most negative to the most positive values, for a given size category of deep convective cloud objects, boundary-layer cumulus, stratocumulus and overcast cloud objects. The PDFs of cloud and radiative properties for deep convective cloud objects (between 30 S and 30 N) are found to largely similar among the five SST anomaly subsets except for the lowest SST anomaly subset. The different characteristics from this SST anomaly subset may be related to some cloud objects resulting from equatorward movement of extratropical cloud systems. This result holds true for all three different size categories (measured by equivalent diameters of 100-150, 150-300 and > 300 km). The PDFs of cloud and radiative properties for boundary-layer cloud types are more variable for macrophysical properties than for microphysical properties, due probably to different large-scale environments where these cloud objects are formed. Implications of these results for the cloud feedback will also be discussed