Search results for "Econometric"
showing 10 items of 3780 documents
Consumers' willingness to pay for natural food: Evidence from an artefactual field experiment
2018
Abstract Among foods with credence attributes, food with “natural” components have received in the last years particular attention by consumers. This study applies the BDM incentive compatible mechanism to explore young (18–35 years old) consumers’ interest and willingness to pay for chewing gums having the natural attribute. Our analysis shows that over 68% of consumers are interested in the natural attribute and are willing to pay a price premium. We also find that consumers’ higher age and interest in the environment have significant impacts on consumers’ preferences for the natural attribute.
Are children more paternalistic than their mothers when choosing snacks?
2016
International audience; This paper focuses on an experiment in which mothers and their child separately chose between relatively healthy foods (flasks of stewed apples) and relatively unhealthy foods (candy bars). Each participant first filled up a first bag for her/himself, and then, a second one for the other person of the dyad. A simple nutritional message on vitamins and sugar contents of foods was then provided, and subsequently each participant filled up a third bag for her/himself and a fourth one for the other person of the dyad. The results show that before revealing the nutritional message, mothers are, on average, "indulgent", which means that they choose a lower number of relati…
Consumer interest towards tropical fruit: factors affecting avocado fruit consumption in Italy
2017
Abstract The purpose of this paper is to identify the main factors affecting the consumption of avocado fruit among Italian consumers. In order to respond to the aim of the study, an empirical survey was conducted through the submission of an online questionnaire to 327 consumers. An ordered logit econometric model was adopted to examine the relationship among some explanatory variables and the frequency of consumption of avocado fruit. The findings of this study show that the consumption of avocado fruit is affected by different factors, including fruit consumption habit, neophilia attitudes, and various intrinsic and extrinsic quality attributes (credence attributes in particular). The st…
Coupling News Sentiment with Web Browsing Data Improves Prediction of Intra-Day Price Dynamics
2015
The new digital revolution of big data is deeply changing our capability of understanding society and forecasting the outcome of many social and economic systems. Unfortunately, information can be very heterogeneous in the importance, relevance, and surprise it conveys, affecting severely the predictive power of semantic and statistical methods. Here we show that the aggregation of web users' behavior can be elicited to overcome this problem in a hard to predict complex system, namely the financial market. Specifically, our in-sample analysis shows that the combined use of sentiment analysis of news and browsing activity of users of Yahoo! Finance greatly helps forecasting intra-day and dai…
Stagewise pseudo-value regression for time-varying effects on the cumulative incidence
2015
In a competing risks setting, the cumulative incidence of an event of interest describes the absolute risk for this event as a function of time. For regression analysis, one can either choose to model all competing events by separate cause-specific hazard models or directly model the association between covariates and the cumulative incidence of one of the events. With a suitable link function, direct regression models allow for a straightforward interpretation of covariate effects on the cumulative incidence. In practice, where data can be right-censored, these regression models are implemented using a pseudo-value approach. For a grid of time points, the possibly unobserved binary event s…
Prioritizing covariates in the planning of future studies in the meta-analytic framework
2016
Science can be seen as a sequential process where each new study augments evidence to the existing knowledge. To have the best prospects to make an impact in this process, a new study should be designed optimally taking into account the previous studies and other prior information. We propose a formal approach for the covariate prioritization, i.e., the decision about the covariates to be measured in a new study. The decision criteria can be based on conditional power, change of the p-value, change in lower confidence limit, Kullback-Leibler divergence, Bayes factors, Bayesian false discovery rate or difference between prior and posterior expectation. The criteria can be also used for decis…
A deterministic model for highly contagious diseases: The case of varicella
2016
[EN] The classic nonlinear Kermack-McKendrick model based upon a system of differential equations has been widely applied to model the rise and fall of global pandemic and also seasonal epidemic by introducing a forced harmonic infectivity which would change throughout the year. These methods work well in their respective domains of applicability, and for certain diseases, but they fail when both seasonality and high infectivity are combined. In this paper we consider a Susceptible-Infected-Recovered, or SIR, model with two latent states to model the propagation and evolutionary history of varicella in humans. We show that infectivity can be calculated from real data and we find a nonstanda…
Pitfalls of hypothesis tests and model selection on bootstrap samples: Causes and consequences in biometrical applications
2015
The bootstrap method has become a widely used tool applied in diverse areas where results based on asymptotic theory are scarce. It can be applied, for example, for assessing the variance of a statistic, a quantile of interest or for significance testing by resampling from the null hypothesis. Recently, some approaches have been proposed in the biometrical field where hypothesis testing or model selection is performed on a bootstrap sample as if it were the original sample. P-values computed from bootstrap samples have been used, for example, in the statistics and bioinformatics literature for ranking genes with respect to their differential expression, for estimating the variability of p-v…
Stability of stationary solutions in models of the Calvin cycle
2017
Abstract In this paper results are obtained concerning the number of positive stationary solutions in simple models of the Calvin cycle of photosynthesis and the stability of these solutions. It is proved that there are open sets of parameters in the model of Zhu et al. (2009) for which there exist two positive stationary solutions. There are never more than two isolated positive stationary solutions but under certain explicit special conditions on the parameters there is a whole continuum of positive stationary solutions. It is also shown that in the set of parameter values for which two isolated positive stationary solutions exist there is an open subset where one of the solutions is asym…
The Quality Perception of Fresh Berries: An Empirical Survey in the German Market
2016
AbstractThe present work aimed to investigate the main quality attributes that influence the purchase decisions of fresh berries. To this regard, an empirical survey has been conducted by interviewing 200 consumers of fresh berries at the exit of the main centers of the large scale retail trade in the city of Munich (Germany). An econometric model has been adopted to examine the relationship that single attributes has on the purchase frequency of fresh berries. Results showed that nutraceutical properties and health benefits of berries have a strong appeal to the consumers and confirmed that intrinsic attributes are determinants of consumer purchase decision