Half-metallic Ferrimagnetism Driven by Coulomb Enhanced Spin-Orbit Coupling in PdCrO3

Recently, in the seemingly narrow gap insulating NiCrO$_3$ with the trigonally distorted (R-3c) perovskite-like structure, a compensated half-metal (CHM) is predicted, as applying a modest pressure. Using ab initio calculations including both Coulomb correlations and spin-orbit coupling (SOC), we investigate the as-yet-unsynthesized PdCrO$_3$, isostructural and isovalent to NiCrO$_3$. Upon applying the on-site Coulomb repulsion $U$ to both Pd and Cr ions, the Cr spin moment is precisely compensated with the antialigned spin moments of Pd and oxygens. Coincidentally only one spin channel remains metallic due to the twice larger width of the Pd 4d bands than the Ni 3d bands in NiCrO$_3$, indicating CHM in ambient pressure. Inclusion of SOC as well as correlation effects (LDA+U+SOC) produces a SOC constant enhanced twice over the value of LDA+SOC, leading to unusually large orbital moment of --0.25 $\mu_B$ on Pd. However, the half-metallicity still survives, so that a transition of CHM to a half-metallic ferrimagnet occurs due to Coulomb enhanced SOC. On the other hand, an isovalent, but presumed cubic double perovskite La$_2$PdCrO$_6$ is expected to be a half-metal ferromagnet with tiny orbital moments.Comment: 5 pages (in press in Phys. Rev. B

Land Sales and Rental Markets in Transition: Evidence from Rural Vietnam

Impact and desirability of land transfers in post-socialist transition economies have been subject to considerable debate. We use data from Vietnam to identify factors conducive to the development of land markets and to assess potentially differential impacts of rental and sales. Results show that both rental and sales transfer land to more productive producers but that rental is more important for the poor to access land that becomes available as the non-farm economy develops. The fact that secure land rights significantly increase supply of land to the rental market suggests that government has a key role in facilitating emergence and functioning of efficiency-enhancing land markets.Land Economics/Use,

Securing property rights in transition: Lessons from implementation of China's rural land contracting law

While recent studies point towards the importance of institutions, in particular secure property rights, as key determinants of economic growth, options to foster institutional change to make property rights more secure are not well understood. Data from 800 villages all over China on the effectiveness with which a law aiming to increase households' tenure security -at the expense of local leaders' powers to reallocate or expropriate land without adequate compensation- provides an opportunity to identify such factors. Using illegal land reallocations and low compensation payments for expropriated land to identify lack of effective institutional change, we find that the impact of property rights reform is contingent on the institutional constraints imposed on leaders' power by democratic institutions and a clear legal framework, households' knowledge of the law, and to some extent presence of land certificates.Land Economics/Use,

ANALYSIS OF U.S. WHEAT MARKET SHARES IN EAST ASIA

The effects of U.S. wheat prices, dollar values, and their volatilities on U.S. wheat market shares in 10 Asian countries are analyzed. The variables are converted to a relative form comparing the U.S. against Australian and Canadian variables in order to incorporate the effects of competition among these countries. The effects of the increased loan rates and target prices in the early 1980s and the U.S. export enhancement program (EEP) are also analyzed. Estimation results show that higher U.S. wheat prices and U.S. dollar appreciation have detrimental effects, while increases in competitors? wheat prices and currency values have cross positive effects on U.S. market shares. The importers are not sensitive to volatility in annual price and exchange rate changes. Dummy variables representing the domestic farm and trade policies are not statistically significant, implying that the two variables do not have a substantial effect on U.S. wheat export performance in the markets.international wheat trade, market share, panel unit-root test, panel estimation, Crop Production/Industries, International Relations/Trade,

THE EFFECT OF FOOD-SAFETY RELATED INFORMATION ON CONSUMERS' PREFERENCE: THE CASE OF BSE OUTBREAK IN JAPAN

This study analyzes consumers' responses to food-safety related information by evaluating if Japanese consumers have undergone a structural change in their preferences for meat due to the BSE outbreak in the country. The axiom of revealed preference is utilized to test the stability of preference in Japanese meat consumption. The matrix of weak form of revealed preference (WARP) is partitioned and Kruskal-Wallis statistics are derived to evaluate whether the switches of preference are transitory or due to a structural change. Empirical results show that Japanese meat demand has undergone a structural change, synchronized with the BSE outbreak in Japan in mid-September 2001.Food Consumption/Nutrition/Food Safety,