THE THEORY AND ECONOMETRICS OF HEALTH INFORMATION IN CROSS-SECTIONAL NUTRIENT DEMAND ANALYSIS

Understanding the role of health information in food and nutrient demand has become an important issue over the last decade. Endogeneity and measurement error are two empirical problems that are inherent in this type of analysis. While some type of instrumental variables estimation would appear the obvious solution, this paper provides several theoretical and empirical reasons why this is not the case in cross-sectional analysis. An alternative estimation strategy is pursued, an empirical example given, and the implications discussed.Food Consumption/Nutrition/Food Safety,

South Korean Millers’ Preferences for the Quality Characteristics of Hard White Wheat that is Used in Producing All-purpose Flour

Using the choice-based conjoint analysis and self explicated approach, I elicited South Korean millers’ preference and willingness to pay for the quality characteristics of hard white wheat that is used in producing all-purpose flour. In specified seven attributes, test weight, moisture, and price significantly affect to South Korean millers’ utility but protein contents, ash, dockage, and falling number does not. South Korean millers are more willing to pay to change the quality characteristics related to the milling yields and profitability, such as test weight, moisture and dockage. But their willingness-to-pay for protein content is not as big as common expectation. Along with the research of Srinivasan (1997), we found that the self-explicated approach yields a slightly (but not statistically significantly) higher predictive validity than does the choice-based conjoint analysis. The results of this study provide not only guideline of quality standards of hard white wheat, but also focus point that U.S. producers have to intensify among quality characteristics of hard white wheat to create demand in South Korean market.Hard White Wheat, South Korean wheat market, Choice-based conjoint analysis, Self-explicated approach, Conditional logit model, Willingness-to-pay, Agribusiness, Agricultural and Food Policy, Consumer/Household Economics, Crop Production/Industries, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, International Relations/Trade, Marketing, Research Methods/ Statistical Methods,

IMPACTS OF ADVERTISING, ATTITUDES, LIFESTYLES, AND HEALTH ON THE DEMAND FOR U.S. PORK: A MICRO-LEVEL ANALYSIS

Using datat from the 1994-1996 CSFII/DHKS, we identify and assess factors affecting the decision to consume pork and conditional on consuming pork, the decision of the amount of pork intake. Branded and generic advertising of pork play a prominent role in both decisions. Beef advertising, however, does not significantly affect either the probability of consuming pork or the amount of pork intake. Key health, attitudinal and lifestyle factors are smoking status, dietary status, body mass index, the importance of nutrition in buying food, and trimming visible fat from meat. These factors however impact the probability of consuming pork rather than the amount of pork consumed. Region, urbanization, race, age, income, and seasonality also affect pork demand.branded advertising and promotion, CSFII/DHKS (1994-96), generic advertising and promotion, pork demand, pork checkoff, Demand and Price Analysis, Marketing,

Inferring the astrophysics of reionization and cosmic dawn from galaxy luminosity functions and the 21-cm signal

The properties of the first galaxies, expected to drive the Cosmic Dawn (CD) and the Epoch of Reionization (EoR), are encoded in the 3D structure of the cosmic 21-cm signal. Parameter inference from upcoming 21-cm observations promises to revolutionize our understanding of these unseen galaxies. However, prior inference was done using models with several simplifying assumptions. Here we introduce a flexible, physically-motivated parametrization for high-$z$ galaxy properties, implementing it in the public code 21cmFAST. In particular, we allow their star formation rates and ionizing escape fraction to scale with the masses of their host dark matter halos, and directly compute inhomogeneous, sub-grid recombinations in the intergalactic medium. Combining current Hubble observations of the rest-frame UV luminosity function (UV LFs) at high-$z$ with a mock 1000h 21-cm observation using the Hydrogen Epoch of Reionization Arrays (HERA), we constrain the parameters of our model using a Monte Carlo Markov Chain sampler of 3D simulations, 21CMMC. We show that the amplitude and scaling of the stellar mass with halo mass is strongly constrained by LF observations, while the remaining galaxy properties are constrained mainly by 21-cm observations. The two data sets compliment each other quite well, mitigating degeneracies intrinsic to each observation. All eight of our astrophysical parameters are able to be constrained at the level of $\sim 10\%$ or better. The updated versions of 21cmFAST and 21CMMC used in this work are publicly available.Comment: 16 pages, 8 figures and 2 tables. Associated movies are available at http://homepage.sns.it/mesinger/21CMMC.html. Updated to match the published version. All results and conclusions remain unchange

Analysis of recent type Ia supernova data based on evolving dark energy models

We study characters of recent type Ia supernova (SNIa) data using evolving dark energy models with changing equation of state parameter w. We consider sudden-jump approximation of w for some chosen redshift spans with double transitions, and constrain these models based on Markov Chain Monte Carlo (MCMC) method using the SNIa data (Constitution, Union, Union2) together with baryon acoustic oscillation A parameter and cosmic microwave background shift parameter in a flat background. In the double-transition model the Constitution data shows deviation outside 1 sigma from LCDM model at low (z < 0.2) and middle (0.2 < z < 0.4) redshift bins whereas no such deviations are noticeable in the Union and Union2 data. By analyzing the Union members in the Constitution set, however, we show that the same difference is actually due to different calibration of the same Union sample in the Constitution set, and is not due to new data added in the Constitution set. All detected deviations are within 2 sigma from the LCDM world model. From the LCDM mock data analysis, we quantify biases in the dark energy equation of state parameters induced by insufficient data with inhomogeneous distribution of data points in the redshift space and distance modulus errors. We demonstrate that location of peak in the distribution of arithmetic means (computed from the MCMC chain for each mock data) behaves as an unbiased estimator for the average bias, which is valid even for non-symmetric likelihood distributions.Comment: 12 pages, 6 figures, published in the Phys. Rev.

Two Dimensional Poynting Flux Dominated Flow onto a Schwarzschild Black Hole

We discuss the dynamics of the accretion flow onto a black hole driven by Poynting flux in a simplified model of a two-dimensional accretion disk. In this simplified model, the condition of the stationary accretion flow is found to impose a nontrivial constraint on the magnetic field configuration. The effect of the magnetic field on the accretion flow is discussed in detail using the paraboloidal and hyperboloidal type configuration for the poloidal structure suggested by Blandford in 1976. It is demonstrated explicitly that the angular velocity of the disk, $\Omega_D$, deviates from the Keplerian angular velocity. The angular velocity of the rigidly-rotating magnetic surface, $\Omega_F$, does not have to be the same as the angular velocity of the disk for the paraboloidal type configuration. But for the hyperboloidal type configuration, it is found that we can set $\Omega_F = \Omega_D$, which corresponds to an accretion disk of perfect conductor. We discuss the numerical solutions of the stream equation for stationary accretion flow in the Schwarzschild background using a paraboloidal type configuration. The dynamics of the accretion disk is found to depend strongly on the ratio of the accretion rate to the magnetic field strength.Comment: 9 pages, 3 figure