Kuhn-Tucker,likelihood ratio and Wald tests for nonlinear models with inequality constraints on the parameters

This paper considers the problem of testing statistical hypothesis in nonlinear regression models with inequality constraints on the parameters. First, the Kuhn-Tucker test procedure is defined. Next, it is shown that the distribution of the Kuhn-Tucker, the likelihood ratio and the Wald test statistics converges to the same mixture of chi-square distributions under the null hypothesis. To illustrate these results two examples are considered: (1) the problem of testing that individual effects are missing in an error component model, and (2) the problem of testing equilibrium for a model of markets in disequilibrium.     

Routing and refueling plans to minimize travel time in alternative-fuel vehicles

A driver who drives an alternative-fuel vehicle (AFV) from an origin point to a destination point needs to consider how to get there (i.e., the routing problem), when to stop, and how and when to refuel (i.e., the refueling plan). In this study, models and algorithms are proposed that optimize a one-way-trip path such that the total travel time from the origin to the destination is minimized. The travel time consists of the setup time, the refueling time and the driving time. The setup time includes waiting for the AFV to be served at a refueling station and the preparation time of charging the machine. We categorized the problems into two types: (1) the refueling plan problem when the routing decision is given and (2) an integrated problem of routing and refueling. Another axis of categorization is when (1) setup time and refueling times are site-independent and (2) parameters are site-dependent. We propose optimal algorithms for site-independent problems and the integrated problem of routing and refueling planning with site-independent parameters. We also conduct experiments and sensitivity analyses for the site-dependent integrated problems of routing and refueling.     

Case studies in medical futility

Technology has provided means to sustain life and provide care regardless of whether the treatment is appropriate and compassionate given the condition of the patient. This study presents two case histories, compiled from historical patient charts, staff notes and observations, that illustrate the variety of ethical issues involved and the role culture plays in the decision making process related to possible futile medical treatment. Ethical and cultural issues related to the cases are discussed and processes are presented that can help hospitals to avoid, or decrease the level of, medically futile care, and improve the cultural appropriateness of medical care and relationships with patients.     

Killing two birds with one currency: Income and fiscal policies in a growth model of a currency union

Building on a two-country Kaleckian model of a currency union, we examine the consequences of balance-of-payments adjustment policies, focusing on the interdependence between the long-run growth paths of member countries. The model separates the short-run from the long-run dynamic, comparing price and wage dynamics in each country in the light of Thirlwall’s balance-of-payments-constrained growth model. We show that by shifting the burden of adjustment to the less competitive country, austerity and wage moderation policies lead to long-term recessionary effects. Only expansionary policies in the more competitive country can achieve the two goals of reducing external imbalances and increasing the long-run growth rate in both member countries.     

Scale Effects,Savings and Factor Shares in a Human Capital-based Growth Model with Physical Capital Accumulation

Using a balanced-growth model with physical and human capital accumulation, we analyze quantitatively the long-run effects of changes in the savings rate and in income distribution (i.e. the shares of physical and human capital in income) on investment in skill acquisition, income growth, and the ratio of human to physical capital. In the long run, the ratio of physical to human capital is constant, so that these two factor inputs can grow at the same rate. This rate is a function of the economy's exogenous technological and preference parameters and depends positively on the share of skills invested in human capital formation. We also find that population growth is neither necessary nor conducive to economic growth, that the level of real income depends linearly on the level of human capital and that it is independent of population size.     

The determinants of pay settlements: the influence of the national context

This article studies the influence of national context and collective bargaining on the factors taken into account when adjusting wages. Using data from Spanish and British manufacturing establishments, we examine the relative importance of the cost of living, the ability to recruit or retain employees, the financial performance of the organisation and the industrial relations climate on wage adjustments of manual workers at the establishment level. Our findings show that there are significant differences on the importance given to these factors in both countries. In part, these are related to differences in the incidence of collective bargaining.     

Investment decisions,net present value and bounded rationality

The Net Present Value maximizing model has a respectable ancestry and is considered by most scholars to be a theoretically sound decision model. In real-life applications, decision makers use the NPV rule, but apply a subjectively determined hurdle rate, as opposed to the ‘correct’ opportunity cost of capital. According to a heuristics-and-biases-program approach, this implies that the hurdle-rate rule is a biased heuristic. This work shows that the hurdle-rate rule may be interpreted as a fruitful strategy of bounded rationality, where several domain-specific and project-specific elements are integrated and condensed into an aspiration level. The paper also addresses the issue of a productive cooperation between bounded and unbounded rationality.     

The Well-Being Cost of Inflation Inequalities

In terms of well-being, how costly is inflation? To answer this question, empirical evaluations have typically studied average inflation rates at the national level, thus disregarding the role of inflation inequalities within a country. In this article, we relax the assumptions that heterogeneous consumers face homogeneous inflation rates, and study the correlation between price changes and self-reported satisfaction with living standards. We use newly available data from France and adopt two approaches. First, we focus on individually perceived inflation and use the internationally harmonized Opinion Price Index as a proxy for experienced inflation. Variations in perceived inflation help predict well-being differences among consumers, even when controlling for relevant sociodemographic factors, personality traits, and common method variance. We estimate their marginal impact to be higher than equivalent variations in nominal income. Second, we compare groups of consumers over time and find that changes in the price of a good disproportionately affect the relative well-being of those who consume it. The study shows that the well-being cost of the inflation crisis would be underestimated if looking at aggregate figures only.     

Exploring the moderating effect of gender in the relationship between individuals' aspirations and career success among engineers in Peru

Purpose: The aim of this paper is to analyse the relationship between career success and individual career aspirations for engineers, and to test whether this differs according to gender. The primary hypothesis in this research is that gender does make a significant difference.

Design/methodological/approach: The sample consists of 1011 engineers who graduated from a prestigious Peruvian college between 1998 and 2005. Female graduates constituted only 4% of the sample, which is similar to the national statistics for engineers in Peru during this period. The relationships were primarily tested using multiple regression and structural equation modelling analyses.

Findings: Findings show a positive relationship between individual career aspirations and career success for men, but not necessarily for women; this supports the hypothesis that gender moderates this relationship. Females seek more secure career orientation than their male counterparts. In addition, females have shown that their career success is more related to feminine themes such as achieving ‘work–family balance’. The findings are in line with previously published results in other countries in which female engineers have career orientations with a preference for a balance between work and family as well as work stability.

Research limitations/implications: The sample is limited to graduates from a single Peruvian college of engineering. Although the sample has similar demographic characteristic to a national population, a more heterogeneous sample is called for in a future research. Moreover, additional moderators should be incorporated, such as family background, residency (large urban cities vs. small villages) and perhaps other variables.

Practical implications: Results can help Human Resource Managers to design better career plans, which consider gender in defining policies for the attraction and retention of competent female engineers.