The environmental implications of airlines' choice of aircraft size

One of the main outcomes of open skies policies is the importance of service frequency in the competition between airlines. To keep load factors high while offering high frequency service, airlines tend to reduce the size of the aircraft used. On short-haul routes this phenomenon is even more apparent, especially on routes between hub airports, even though these routes and airports are often congested. This choice of service frequency and aircraft size must have important environmental consequences that this paper aims to evaluate and quantify. The analysis considers local air pollution, climate change and noise impacts and aims to evaluate whether the competitive environment that drives airlines to offer high frequency service carries an environmental penalty. The analysis showed that increasing aircraft size and adjusting the service frequency to offer similar seating capacity will increase local pollution but decrease climate change impact and noise pollution. When local pollution and climate change impacts are monetized and aggregated the analysis showed that environmental benefits will result from increasing aircraft size. But these benefits, in monetary terms, were found to be relatively small and sensitive to the assumptions made.     

Visions for a walking and cycling focussed urban transport system

Walking and cycling can make a considerable contribution to sustainable transport goals, building healthier and more sustainable communities and contributing to traffic and pollution reduction. There have been many national and local initiatives to promote walking and cycling, but without a long term vision and consistent strategy it is difficult to see how a significant change may be achieved. This paper presents three alternative visions for the role of walking and cycling in urban areas for the year 2030: each vision illustrates a ‘desirable’ walking- and cycling-oriented transport system against a different ‘exogenous social background’. These visions have been developed through a process of expert discussion and review and are intended to provide a stimulus for debate on the potential for and desirability of such alternative futures. Each is based on the UK and represents a substantial change to the current situation: in particular, each of the visions presents a view of a society where walking and cycling are considerably more important than is currently the case and where these modes cater for a much higher proportion of urban transport needs than at present. The visions show pictures of urban environments where dependence on motor vehicles has been reduced, in two of the visions to very low levels. The methodological approach for devising visions is informed by work on ‘utopian thinking’: a key concept underlying this approach is one of viewing the future in social constructivist terms (i.e. the future is what ‘we’, as a society, make it) rather than considering the future as something that can be ‘scientifically’ predicted by the extrapolation of current trends.     

Unlocking the potential of unoccupied spectrum in developing countries: Southern African Development Community – case study

The lack of adequate telecommunications infrastructure in developing regions makes wireless systems the most feasible solution for providing Internet connectivity. With the global migration of television (TV) systems from analogue to digital, the TV spectrum is expected to be shared between broadcasting and broadband services. However, the absence of suitable regulatory policies for TV band sharing and low average revenue per user experienced by wireless network operators makes it difficult to deploy broadband networks in developing regions, especially in rural areas. This article presents a co-evolution analysis of three key domains of change (policy, technology and business) in providing broadband connectivity focusing on the Southern African Development Community region. Furthermore, the article proposes public–private partnership and public–private–people partnership models for deploying wireless broadband networks in developing regions. This article is useful to various stakeholders, including policy-makers, governments, the wireless communications industry and academia, by addressing the digital divide in developing regions.     

Co-monotonicity: Toward a utility function capturing envy

Envy affects economic decisions, and can lead to monotonicity violation. We introduce co-monotonicity—a generalization of monotonicity, expected to hold even in the presence of envy. Experimental results and implications for the form of possible utility functions are discussed.     

Why did rich families increase their fertility? Inequality and marketization of child care

A negative relationship between income and fertility has persisted for so long that its existence is often taken for granted. One economic theory builds on this relationship and argues that rising inequality leads to greater differential fertility between rich and poor. We show that the relationship between income and fertility has flattened between 1980 and 2010 in the US, a time of increasing inequality, as high income families increased their fertility. These facts challenge the standard theory. We propose that marketization of parental time costs can explain the changing relationship between income and fertility. We show this result both theoretically and quantitatively, after disciplining the model on US data. We explore implications of changing differential fertility for aggregate human capital. Additionally, policies, such as the minimum wage, that affect the cost of marketization, have a negative effect on the fertility and labor supply of high income women. We end by discussing the insights of this theory to the economics of marital sorting.     

Variety seeking,market partitioning and segmentation

This paper ties together hierarchical partitioning of product markets, segmentation and variety seeking. Individual variety seeking is shown to be a more meaningful partitioning criterion than simple aggregate brand switching. Variety seeking is attribute dependent and thus should not be directly related to the consumer's socio-economic and demographic characteristics. Alternatively, the consumer's way of partitioning the market is suggested as a useful criterion for segmentation.     

Substitution and scale effects with and without homotheticity: An application to the intertemporal consumption decision

This paper derives a simple functional relation between substitution and scale concepts applicable to the theories of consumption and production. Its usefulness is illustrated by pulling together various results about the relation between savings and the interest rate.     

STOCHASTIC DOMINANCE AND TRUNCATED SAMPLE DATA

The purpose of this paper is to examine whether the chance of making erroneous investment decisions can be reduced by applying stochastic dominance rules to truncated, rather than complete, sample data of rates of return. A simulation approach is used that assumes the rates of return follow the symmetric stable probability distribution. Using a variety of relationships between probability distributions of rates of return, it is demonstrated that sample truncation has the potential of significantly reducing sampling errors in the selection between alternative investments.