Estimation of value of travel-time savings using mixed logit models

In this paper, we discuss some of the issues that arise with the computation of the implied value of travel-time savings in the case of discrete choice models allowing for random taste heterogeneity. We specifically look at the case of models producing a non-zero probability of positive travel-time coefficients, and discuss the consistency of such estimates with theories of rational economic behaviour. We then describe how the presence of unobserved travel-experience attributes or conjoint activities can bias the estimation of the travel-time coefficient, and can lead to false conclusions with regards to the existence of negative valuations of travel-time savings. We note that while it is important not to interpret such estimates as travel-time coefficients per se, it is nevertheless similarly important to allow such effects to manifest themselves; as such, the use of distributions with fixed bounds is inappropriate. On the other hand, the use of unbounded distributions can lead to further problems, as their shape (especially in the case of symmetrical distributions) can falsely imply the presence of positive estimates. We note that a preferable solution is to use bounded distributions where the bounds are estimated from the data during model calibration. This allows for the effects of data impurities or model misspecifications to manifest themselves, while reducing the risk of bias as a result of the shape of the distribution. To conclude, a brief application is conducted to support the theoretical claims made in the paper

Collaborative Engagement Approaches For Delivering Sustainable Infrastructure Projects In The AEC Sector: A Review

The public sector has traditionally financed and operated infrastructure projects using resources from taxes and various levies (e.g. fuel taxes, road user charges). However, the rapid increase in human population growth coupled with extended globalisation complexities and associated social/political/economic challenges have placed new demands on the purveyors and operators of infrastructure projects. The importance of delivering quality infrastructure has been underlined by the United Nations declaration of the Millennium Development Goals; as has the provision of ‘adequate’ basic structures and facilities necessary for the well-being of urban populations in developing countries. Thus, in an effort to finance developing countries’ infrastructure needs, most countries have adopted some form of public-private collaboration strategy. This paper critically reviews these collaborative engagement approaches, identifies and highlights 10 critical themes that need to be appropriately captured and aligned to existing business models in order to successfully deliver sustainable infrastructure projects. Research findings show that infrastructure services can be delivered in many ways, and through various routes. For example, a purely public approach can cause problems such as slow and ineffective decision-making, inefficient organisational and institutional augmentation, and lack of competition and inefficiency (collectively known as government failure). On the other hand, adopting a purely private approach can cause problems such as inequalities in the distribution of infrastructure services (known as market failure). Thus, to overcome both government and market failures, a collaborative approach is advocated which incorporates the strengths of both of these polarised positions

The Economics of Water Resource Allocation: Valuation Methods and Policy Implications

In this chapter a ‘watershed economics approach’ that could be applied in Cyprus is proposed which is composed of two important stages. In Stage I economic valuation techniques are used to establish the economic value of the competing demands for surface and groundwater, incorporating where necessary an analysis of water quality. The valuation exercise allows the objective balancing of demands based upon the equi-marginal principle to achieve economic efficiency. In Stage II a policy impact analysis is proposed which addresses issues of social equity and the value of water for environmental/ecological purposes. The analysis is undertaken within the confines of the watershed; the most natural unit for the analysis of water allocation and scarcity since it determines the hydrological links between competing users and thus the impacts of one user upon another. The methodology is encapsulated by a case study of the Kouris watershed in Cyprus

Optimising workplace interventions for health and wellbeing: a commentary on the limitations of the public health perspective within the workplace health arena [forthcoming]

Purpose: This paper discusses contemporary approaches to workplace health and well-being, articulating key differences in the intervention architecture between public and workplace health contexts and implications for intervention design. Approach: Contemporary practice is discussed in light of calls for a paradigm shift in occupational health from a treatment orientation to an holistic approach focused on mitigation of the causes of ill health and the promotion of well-being. In practice, relatively few organizations have or seem able to engage with a broader perspective that encompasses challenges to health and well-being associated with contextual organizational drivers, e.g. job design/role, workload, systems of reward, leadership style and the underpinning climate. Drawing upon insights from public health and the workplace safety tradition, the scope for broadening the perspective on intervention (in terms of vectors of harm addressed, theory of change and intervention logic) is discussed. Findings: There are important differences in scope and options for intervention between public health and workplace health contexts. While there is scope to emulate public health practice, this should not constrain thinking over intervention opinions. Increased awareness of these key differences within work organizations, and an evidence-based epidemiological approach to learning has the potential to strengthen and broaden the approach to workplace health and well-being management. Originality/Value: We argue that approaches to workplace well-being interventions that selectively cross-fertilise and adapt elements of public health interventions offer promise for realising a broader change agenda and for building inherently healthy workplaces

Adaptive Network Coding for Scheduling Real-time Traffic with Hard Deadlines

We study adaptive network coding (NC) for scheduling real-time traffic over a single-hop wireless network. To meet the hard deadlines of real-time traffic, it is critical to strike a balance between maximizing the throughput and minimizing the risk that the entire block of coded packets may not be decodable by the deadline. Thus motivated, we explore adaptive NC, where the block size is adapted based on the remaining time to the deadline, by casting this sequential block size adaptation problem as a finite-horizon Markov decision process. One interesting finding is that the optimal block size and its corresponding action space monotonically decrease as the deadline approaches, and the optimal block size is bounded by the "greedy" block size. These unique structures make it possible to narrow down the search space of dynamic programming, building on which we develop a monotonicity-based backward induction algorithm (MBIA) that can solve for the optimal block size in polynomial time. Since channel erasure probabilities would be time-varying in a mobile network, we further develop a joint real-time scheduling and channel learning scheme with adaptive NC that can adapt to channel dynamics. We also generalize the analysis to multiple flows with hard deadlines and long-term delivery ratio constraints, devise a low-complexity online scheduling algorithm integrated with the MBIA, and then establish its asymptotical throughput-optimality. In addition to analysis and simulation results, we perform high fidelity wireless emulation tests with real radio transmissions to demonstrate the feasibility of the MBIA in finding the optimal block size in real time.Comment: 11 pages, 13 figure

MECHANISMS OF GOVERNANCE OF SUSTAINBLE DEVELOPMENT

In this paper we incorporate the interdisciplinary New Institutional and Transaction Costs Economics (combining Economics, Organization, Law, Sociology, Behavioural and Political Sciences), and suggest a framework for analyzing the mechanisms of governance of sustainable development. Our new approach takes into account the role of specific institutional environment; and the behavioural characteristics of individual agents (personal preferences, bounded rationality, tendency for opportunism, trust, risk aversion); and the transaction costs associated with the various forms of governance; and the critical factors of economic activity and exchanges (such as appropriability, frequency, uncertainty, and asset specificity of transactions); and the comparative efficiency of market, private, public and hybrid modes; and the potential of production structures for adaptation; and the comparative efficiency of alternative modes for public intervention. Agricultural sector is used to illustrate that new approach and support with examples.institutions, market, private, public and hybrid modes, agrarian sustainability

Decision-focussed resource modelling for design decision support

Resource management including resource allocation, levelling, configuration and monitoring has been recognised as critical to design decision making. It has received increasing research interests in recent years. Different definitions, models and systems have been developed and published in literature. One common issue with existing research is that the resource modelling has focussed on the information view of resources. A few acknowledged the importance of resource capability to design management, but none has addressed the evaluation analysis of resource fitness to effectively support design decisions. This paper proposes a decision-focused resource model framework that addresses the combination of resource evaluation with resource information from multiple perspectives. A resource management system constructed on the resource model framework can provide functions for design engineers to efficiently search and retrieve the best fit resources (based on the evaluation results) to meet decision requirements. Thus, the system has the potential to provide improved decision making performance compared with existing resource management systems

An Integrated Assessment Framework for Water Resources Management: A DSS Tool and a Pilot Study Application

Decision making for the management of water resources is a complex and difficult task. This is due to the complex socio-economic system that involves a large number of interest groups pursuing multiple and conflicting objectives, within an often intricate legislative framework. Several Decision Support Systems have been developed but very few have indeed proved to be effective and truly operational. MULINO (Multisectoral, Integrated and Operational Decision Support System for Sustainable Use of Water Resources at the Catchment Scale) is a project funded under the Fifth Framework Programme of the European Research and the key action line dedicated to operational management schemes and decision support system for sustainable use of water resources. The MULINO DSS (mDSS) integrates hydrological models with multi-criteria decision methods and adopts the DPSIR (Driving Force – Pressure – State – Impact – Response) framework developed by the European Environment Agency. The DPSIR was converted from a static reporting scheme into a dynamic framework for integrated assessment modelling (IAM) and multi-criteria evaluation procedures. This paper presents the methodological framework and the intermediate results of the mDSS tool through its application in a pilot study area located in the Watershed of the Lagoon of Venice.Integrated water resources management, Spatial decision-making, Decision support system, Catchment, Environmental modelling