A Quadratic Generalization of the Almost Ideal and Translog Demand Systems: An Application to Food Demand in Urban China

A new demand system, the QGAITL model, nesting the quadratic almost ideal, translog and LES models as its special cases, is introduced and estimated in this paper. Employing urban household data of four major food items from Jiangsu China in 2001, empirical evidence from both in-sample evaluations and out-of-sample forecasting comparisons shows that the QGAITL is superior to its nested models, whether or not demographic effects are incorporated.Demand and Price Analysis,

IMPACTS OF INCOME CHANGES AND MODEL SPECIFICATION ON FOOD DEMAND IN URBAN CHINA

Functional form specification is a crucial task in demand analysis. Four food demand systems for 12 aggregated food items in urban China are estimated and compared using province level data for the period 1992-1999. The results show the expenditure elasticities especially for grain are different based on the functional form selection. According to the measures of forecasting accuracy, we conclude the following: for ex post simulation, the simpler the models, the better the performances, whereas for ex ante forecasting, the more complicated the model, the better the predictions. We further conclude that the LES and QES outperform the LA/AIDS and AIDS. Therefore, model selection should depend on the study purpose. In addition, as urban Chinese household income increases, they will consume more aquatic products, poultry and milk than other foods. This potential trend will certainly benefit the fishery and livestock industries as well as feed grain producers in China or other countries such as Taiwan. However, high own-price elasticities of these three food groups suggest that the profitability of suppliers and traders is very sensitive to price changes.Demand and Price Analysis,

FOOD DEMAND IN URBAN CHINA: AN APPLICATION OF A MULTI-STAGE CENSORED DEMAND SYSTEM

Since its economic reform, China has changed significantly as it makes its transition from a centrally-planned to a consumer-oriented economy and thus has gradually increased household income and changed consumption patterns in urban China. This study attempts to provide an in-depth understanding of heterogeneous consumer patterns in urban China by developing a multi-stage censored demand system using household data. Specifically, this study develops an economic model considering heterogeneous consumption patterns across households and commodity groupings and estimates econometric models of a Quadratic Almost Ideal Demand System (QAIDS) using household data. Three methodologies are integrated including constructing a multi-stage demand system, incorporating demographic variables using the 'ordinary budget share scaling and translation' (OBSSAT), and employing a two-step estimator to deal with zero consumption problems. This study covers three provinces in China, Shandong, Jiangsu, and Guangdong, and uses household data from 1998 provided by the National Bureau of Statistics (NBS). Based on the Chinese food guide pyramid, a three-level utility tree is constructed dividing 18 food items into five subgroups. An empirical analysis is conducted by estimating econometric models to examine the impact of the potential factors, e.g., income and demographic variables, on food demand. The results show the uniqueness of this study in three dimensions. First, using the OBSSAT helps answer the question of "how to break down the heterogeneous consumption patterns in urban China?" In addition, our findings also show that China should be treated as several markets instead of one. Second, the QAIDS has not previously been applied to the study of food demand in urban China. Our results show that the QAIDS is superior to the AIDS; however, the degree of importance for the quadratic term decreases as demographic and censoring effects are considered in a demand system. Finally, 18 food items are broken down into five food subgroups and are estimated by a multi-stage censored QAIDS. Including this large food bundle in a demand system provides us detailed information of the relationship among food items.Demand and Price Analysis,

TRANSLATING AND SCALING OF BUDGET SHARES: AN EMPIRICAL ANALYSIS OF CHINESE URBAN HOUSEHOLD DEMAND FOR MEAT

The importance of incorporating demographic effects into a demand system is demonstrated using Lewbel's unified functions. In this study, the empirical analysis of meat demand in urban China shows the benefit of utilizing the translation and scaling of budget shares.Demand and Price Analysis,

A Globally Flexible, Quadratic Almost Ideal Demand System: An Application for Meat Demand in Taiwan

A new demand system, combining the quadratic almost ideal demand system and the Fourier expenditure system, is introduced. An application for meat consumption in Taiwan indicates that the new demand system fits the data well and that the restriction to the usual specifications, such as locally flexible functional form, linear Engel curve, and both, are rejected.Food Consumption/Nutrition/Food Safety,

Patient acceptability, safety and access : A balancing act for selecting age-appropriate oral dosage forms for paediatric and geriatric populations

© 2017 Elsevier B.V. All rights reserved.The selection and design of age-appropriate formulations intended for use in paediatric and geriatric patients are dependent on multiple factors affecting patient acceptability, safety and access. The development of an economic and effective product relies on a balanced consideration of the risks and benefits of these factors. This review provides a comprehensive and up-to-date analysis of oral dosage forms considering key aspects of formulation design including dosage considerations, ease of use, tolerability and safety, manufacturing complexity, stability, supply and cost. Patient acceptability has been examined utilising an evidence-based approach to evaluate regulatory guidance and literature. Safety considerations including excipients and potential risk of administration errors of the different dosage forms are also discussed, together with possible manufacturing and supply challenges. Age appropriate drug product design should consider and compare i) acceptability ii) safety and iii) access, although it is important to recognise that these factors must be balanced against each other, and in some situations a compromise may need to be reached when selecting an age-appropriate formulation.Peer reviewedFinal Accepted Versio

Consumer Awareness of the Avian Influenza Threat in Taiwan

Replaced with revised version of paper 06/19/07.consumer awareness, risk perceptions, avian influenza, Taiwan, Consumer/Household Economics, Livestock Production/Industries, M30,

Plug-and-Play Methods Provably Converge with Properly Trained Denoisers

Plug-and-play (PnP) is a non-convex framework that integrates modern denoising priors, such as BM3D or deep learning-based denoisers, into ADMM or other proximal algorithms. An advantage of PnP is that one can use pre-trained denoisers when there is not sufficient data for end-to-end training. Although PnP has been recently studied extensively with great empirical success, theoretical analysis addressing even the most basic question of convergence has been insufficient. In this paper, we theoretically establish convergence of PnP-FBS and PnP-ADMM, without using diminishing stepsizes, under a certain Lipschitz condition on the denoisers. We then propose real spectral normalization, a technique for training deep learning-based denoisers to satisfy the proposed Lipschitz condition. Finally, we present experimental results validating the theory.Comment: Published in the International Conference on Machine Learning, 201