Velocities hasten to tell us about the Universe

The peculiar velocities of galaxies are driven by gravity, and hence hold the promise of probing details of how gravity forms structures. In particular it is possible to constrain cosmological parameters and to test extensions to the standard model, such as modifications to the theory of gravity or the existence of primordial density perturbations which are non-Gaussian. This constraining power has been frustrated by systematic effects, but we appear to be entering an era when velocity measurements may finally be living up to their promise.Comment: A review article of 6 pages and 8 figure

LIVESTOCK PRODUCT CONSUMPTION PATTERNS IN URBAN AND RURAL CHINA

Chinese livestock products consumption behavior was analysed for both urban and rural households using a complete regional consumption dataset. Six livestock product expenditure share equations were estimated with an extended AIDS model. The results suggest that Chinese consumers will continue to increase their consumption of livestock products, but consumption patterns have changed in the 1990s. A large percentage of household livestock product expenditure is still on pork. However, the shares for beef, dairy products and poultry consumption will increase substantially. As a consequence the pork expenditure share will be gradually reduced as incomes grow and diet preferences change in both urban and rural households. There are significant differences in livestock product consumption preferences across provinces of China. As a result, studies that omit regional dummy variables in their demand systems can produce different expenditure and price parameters, which should be interpreted with caution.Food Consumption/Nutrition/Food Safety,

Livestock in China: Commodity specific total factor productivity decomposition using new panel data

Studies of total factor productivity in livestock production are rare, but when available provide useful information especially in the context of developing countries such as China where livestock is becoming more important in the domestic agricultural economy. We estimate total factor productivity (TFP) for four major livestock products in China employing the stochastic frontier approach, and decompose productivity growth into its technical efficiency and technical progress components. Efforts are made to adjust and augment the available livestock statistics. The results show that growth in TFP and its components varied between the 1980s and the 1990s as well as over production structures. While there is evidence of considerable technical innovation in China's livestock sector, technical efficiency improvement has been relatively slow.Stochastic production frontier, total factor productivity, technical efficiency and progress, China, livestock, adjusted panel data, Livestock Production/Industries, D240, Q100, Q160,

Chinese animal product consumption in the 1990s

Chinese animal product consumption behaviour was analysed for both urban and rural households using a complete regional consumption dataset that was augmented to include away‐from‐home consumption. Seven animal product expenditure share equations were estimated with an extended Almost Ideal Demand System model. The results suggest that Chinese consumers will continue to increase their consumption of animal products, but that consumption patterns have changed in the 1990s. A large percentage of household animal product expenditure is still on pork. However, the shares for aquatic and poultry products consumption will increase substantially. As a consequence, the pork expenditure share will be gradually reduced as incomes grow and diet preferences change in both urban and rural households. There are significant differences in animal product consumption preferences across regions of China. As a result, studies that omit regional dummy variables in their demand systems can produce different expenditure and price parameters. The present paper also found that many of the estimates of elasticities and marginal expenditure shares would be rather different if the data ignored consumption away from home.Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

Why Farmers Opt Not to Enroll in Payment-for-Environmental-Services Programs

Payment-for-environmental-services (PES) programs are the focus of increasing attention globally. While existing PES programs can observe who participates and who does not, the reasons for nonparticipation can be opaque. Taking advantage of a unique stated preference data set that includes a follow-up question on conditions for participation, this study differentiates two types of non-participants, those deterred by insufficient payments, and those deterred by fundamental incompatibility with the farm operation. Survey weighted and spatially weighted probit models are applied to examine the determinants of farmers’ willingness to enroll in PES programs and their willingness to consider enrollment at the same or a high payment. Results suggest the decision to enroll relies more on farm benefit-cost factors, such as program payment, total land area and current farming practice, while the decision to consider enrolling depends more on farm and operator characteristics, such as environmental attitudes, soil traits, current government program enrollment or commitment to organic farming. Both decisions also show evidence of spatial dependence that suggest spill-over effects due to natural resources, interpersonal communication, or other socio-economic factors. These findings elucidate reasons for non-participation in PES programs and provide insights for future program design and targeting.Payment-for-environmental-services, agricultural policy, non-participation, working land, stated preference, spatial probit, Agricultural and Food Policy, Environmental Economics and Policy, Production Economics, Q18, Q51, Q57,

Probing the diffuse baryon distribution with the lensing-tSZ cross-correlation

Approximately half of the Universe's baryons are in a form that has been hard to detect directly. However, the missing component can be traced through the cross-correlation of the thermal Sunyaev-Zeldovich (tSZ) effect with weak gravitational lensing. We build a model for this correlation and use it to constrain the extended baryon component, employing data from the Canada France Hawaii Lensing Survey and the {\it Planck\/} satellite. The measured correlation function is consistent with an isothermal $\beta$-model for the halo gas pressure profile, and the 1- and 2-halo terms are both detected at the 4$\sigma$ level. In addition, we measure the hydrostatic mass bias $(1-b)=0.79^{+0.07}_{-0.10}$, which is consistent with numerical simulation results and the constraints from X-ray observations. The effective temperature of the gas is found to be in the range ($7\times10^{5}$--$3 \times10^{8}$)\,K, with approximately $50\%$ of the baryons appearing to lie beyond the virial radius of the halos, consistent with current expectations for the warm-hot intergalactic medium.Comment: 12 pages, 6 figures, 3 tabl