Stochastic orderings of convolution residuals

In this paper we study convolution residuals, that is, if $X_1,X_2,\ldots ,X_n$ are independent random variables, we study the distributions, and the properties, of the sums $\sum _{i=1}^lX_i-t$ given that $\sum _{i=1}^kX_i>t$ , where $t\in \mathbb R $ , and $1\le k\le l\le n$ . Various stochastic orders, among convolution residuals based on observations from either one or two samples, are derived. As a consequence computable bounds on the survival functions and on the expected values of convolution residuals are obtained. Some applications in reliability theory and queueing theory are described.     

An evolutionary model of the size distribution of firms

An analytical study of the evolution of the distribution of firm size in an industry is presented. A drift-diffusion model is proposed to express the time-evolution of density of firm size within the industry. The model blends the conventional, more or less static, determinants with the kinds of dynamic considerations introduced by stochastic processes of evolutionary dynamics. The steady-state distribution as well as the dynamic behavior of the model are derived. Parameters in the resulting analytical expressions are then fit to a population of firms in the non-manufacturing service sector. The empirical portion of the paper validates the proposed evolutionary model.     

Children’s Food Choice: Advertised Food Type,Health Knowledge and Entertainment

The purpose of this research is to examine how the moderating effects of health knowledge (inactive vs. active) and advertising’s entertainment level (high vs. low) affect children’s response to advertising’s food content (unhealthy vs. healthy). First, a primary study using the qualitative method was conducted with the purpose of identifying healthy and unhealthy food options based on culture, eating habits, nutritional value and the access of Iranian children to each option so that they could be displayed in TV advertising, advergames and questionnaires. Then, a 2 × 2 × 2 full-factorial, randomized, mixed-effects experimental design was used to test the research framework. 330 students (aged 6–11) participated in the study. The findings revealed that children tended to choose more unhealthy foods after exposure to unhealthy food advertising. This effect was greater for a higher level of entertainment, and was successfully moderated by the activation of health knowledge. It was concluded that embedding health messages in advertising (included TV advertising and advergames) help retrieving children’s health knowledge and therefore, choosing less unhealthy food by them.     

Airline in-flight entertainment: the passengers’ perspective

Following relaxation of economic regulation in many aviation markets, the competition amongst airlines has intensified in recent years. This has resulted in improvements in airline products, especially in the in-flight services. One of the areas on which airlines have focused their attention is the provision of personal in-flight entertainment (IFE). In 1998, airlines spent $1.8 billion on IFE. However, the industry is faced with a number of questions in relation to such levels of investment: Are the investments justified? Does IFE influence passengers’ choice of airline? Does IFE have a revenue-generating potential? What does the future hold as far as the IFE services are concerned? This paper addresses these questions based on a passengers survey and literature review. The results indicate that while IFE is not amongst the primary factors affecting passengers’ choice, it contributes greatly to passengers’ satisfaction with airline services. While provision of IFE can currently act as a differentiating factor, in the future it will become part of passengers’ expectations. It has also become apparent that, while IFE has the potential to generate some revenue, it would not be enough to cover the total costs associated with the installation and running of IFE systems. The impact of IFE would be felt, indirectly, through increase in passenger loyalty which should have a positive impact on airline revenues.     

A Dynamic Model of Size Distribution of Firms Applied to U.S. Biotechnology and Trucking Industries

The present paper attempts to contribute to the existing literature on industry dynamics by proposing a tractable structure for the analysis of the dynamic process governing the size distribution of firms. An analytical model is proposed which describes the density of the cross-sectional distribution of firm size within an industry. The model is based on the theory of diffusion processes, and the method illustrates how information on the time-evolution of size distribution of firms over an extended period of time can be used to make inferences about an underlying process. An empirical application to the evolution of size distribution of population of firms in (i) the U.S. biotechnology industry, and (ii) the U.S. interstate for-hire trucking industry illustrates the applicability of the proposed model in industry studies.     

Emissions Pricing Policies and Business Cycles: Fixed vs. Variable Tax Regimes

As by-products, emissions follow economic fluctuations. Ignoring this fact in environmental policies can lead to unexpected emissions fluctuations and an increase in intervention costs. Using a real business cycle model, we compare two policies: a fixed tax policy where the price is constant over time and a variable tax regime where the tax rate is set at the beginning of each period. We find that while both programs result in lower emissions, a variable tax regime is preferable since first, it can ensure that the maximum welfare is always achieved, and second, it is more effective in stabilising emissions.