Methodological and empirical challenges in modelling residential location choices

The modelling of residential locations is a key element in land use and transport planning. There are significant empirical and methodological challenges inherent in such modelling, however, despite recent advances both in the availability of spatial datasets and in computational and choice modelling techniques. One of the most important of these challenges concerns spatial aggregation. The housing market is characterised by the fact that it offers spatially and functionally heterogeneous products; as a result, if residential alternatives are represented as aggregated spatial units (as in conventional residential location models), the variability of dwelling attributes is lost, which may limit the predictive ability and policy sensitivity of the model. This thesis presents a modelling framework for residential location choice that addresses three key challenges: (i) the development of models at the dwelling-unit level, (ii) the treatment of spatial structure effects in such dwelling-unit level models, and (iii) problems associated with estimation in such modelling frameworks in the absence of disaggregated dwelling unit supply data. The proposed framework is applied to the residential location choice context in London. Another important challenge in the modelling of residential locations is the choice set formation problem. Most models of residential location choices have been developed based on the assumption that households consider all available alternatives when they are making location choices. Due the high search costs associated with the housing market, however, and the limited capacity of households to process information, the validity of this assumption has been an on-going debate among researchers. There have been some attempts in the literature to incorporate the cognitive capacities of households within discrete choice models of residential location: for instance, by modelling households’ choice sets exogenously based on simplifying assumptions regarding their spatial search behaviour (e.g., an anchor-based search strategy) and their characteristics. By undertaking an empirical comparison of alternative models within the context of residential location choice in the Greater London area this thesis investigates the feasibility and practicality of applying deterministic choice set formation approaches to capture the underlying search process of households. The thesis also investigates the uncertainty of choice sets in residential location choice modelling and proposes a simplified probabilistic choice set formation approach to model choice sets and choices simultaneously. The dwelling-level modelling framework proposed in this research is practice-ready and can be used to estimate residential location choice models at the level of dwelling units without requiring independent and disaggregated dwelling supply data. The empirical comparison of alternative exogenous choice set formation approaches provides a guideline for modellers and land use planners to avoid inappropriate choice set formation approaches in practice. Finally, the proposed simplified choice set formation model can be applied to model the behaviour of households in online real estate environments.Open Acces

Foundations of Behavioral and Experimental Economics: Daniel Kahneman and Vernon Smith

Advanced information on the Prize in Economic Sciences 2002. Until recently, economics was widely regarded as a non-experimental science that had to rely on observation of real-world economies rather than controlled laboratory experiments. Many commentators also found restrictive the common assumption of a homo oeconomicus motivated by self-interest and capable of making rational decisions. But research in economics has taken off in new directions. A large and growing body of scientific work is now devoted to the empirical testing and modification of traditional postulates in economics, in particular those of unbounded rationality, pure self-interest, and complete self-control. Moreover, today's research increasingly relies on new data from laboratory experiments rather than on more traditional field data, that is, data obtained from observations of real economies. This recent research has its roots in two distinct, but converging, traditions: theoretical and empirical studies of human decision-making in cognitive psychology, and tests of predictions from economic theory by way of laboratory experiments. Today, behavioral economics and experimental economics are among the most active fields in economics, as measured by publications in major journals, new doctoral dissertations, seminars, workshops and conferences. This year's laureates are pioneers of these two fields of research.behavioral economics; experimental economics

Scalable Semantic Matching of Queries to Ads in Sponsored Search Advertising

Sponsored search represents a major source of revenue for web search engines. This popular advertising model brings a unique possibility for advertisers to target users' immediate intent communicated through a search query, usually by displaying their ads alongside organic search results for queries deemed relevant to their products or services. However, due to a large number of unique queries it is challenging for advertisers to identify all such relevant queries. For this reason search engines often provide a service of advanced matching, which automatically finds additional relevant queries for advertisers to bid on. We present a novel advanced matching approach based on the idea of semantic embeddings of queries and ads. The embeddings were learned using a large data set of user search sessions, consisting of search queries, clicked ads and search links, while utilizing contextual information such as dwell time and skipped ads. To address the large-scale nature of our problem, both in terms of data and vocabulary size, we propose a novel distributed algorithm for training of the embeddings. Finally, we present an approach for overcoming a cold-start problem associated with new ads and queries. We report results of editorial evaluation and online tests on actual search traffic. The results show that our approach significantly outperforms baselines in terms of relevance, coverage, and incremental revenue. Lastly, we open-source learned query embeddings to be used by researchers in computational advertising and related fields.Comment: 10 pages, 4 figures, 39th International ACM SIGIR Conference on Research and Development in Information Retrieval, SIGIR 2016, Pisa, Ital

Risk management strategy of construction projects in China

A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of PhilosophyEmbarking on a construction project means taking a risk. Project risk management (PRM) provides an effective approach to improve decision making and minimise project risk. Project risks may not possess the same level of significance for different countries, markets and projects. Current research on PRM in China has been rather theoretical, addressing technology issues. Considering the current practice in the Chinese construction industry (CCl), the PRM needs understanding and support from the industry and a mature market environment. This research aims to establish PRM strategies for identifying and adopting the best practice to provide practical guidelines for the CCl, thus improving the PRM, motivating the reform of the Chinese construction market, and enabling the CCl to function in the competitive environment of globalisation. An extensive literature review and a number of case studies for construction projects in China have been conducted, addressing issues closely related to the research. A systematic analysis is employed and developed for project planning and decision making. Contractual risks are considered as the first step and catalyst for improving the PRM in the CCl. Built on the findings from the case studies and analysis, the research puts forward a framework of contractual risk management to study the concept, identification and classification of contractual risks. Contract interfaces are analysed for contractual risk management under various project procurement routes (PPRs). The potentially large improvements to the PRM and reform of the Chinese construction market from the introduction and application of innovative PPRs and their contractual conditions are addressed. Two mathematical models -a probabilistic analysis model and an effective information entropy model for key contractual risks -are presented. The validity and applicability of the models are demonstrated with sample data for the CCl. Detailed recommendations and guidelines for the implementation of the proposed strategies are suggested

Chain: A Dynamic Double Auction Framework for Matching Patient Agents

In this paper we present and evaluate a general framework for the design of truthful auctions for matching agents in a dynamic, two-sided market. A single commodity, such as a resource or a task, is bought and sold by multiple buyers and sellers that arrive and depart over time. Our algorithm, Chain, provides the first framework that allows a truthful dynamic double auction (DA) to be constructed from a truthful, single-period (i.e. static) double-auction rule. The pricing and matching method of the Chain construction is unique amongst dynamic-auction rules that adopt the same building block. We examine experimentally the allocative efficiency of Chain when instantiated on various single-period rules, including the canonical McAfee double-auction rule. For a baseline we also consider non-truthful double auctions populated with zero-intelligence plus"-style learning agents. Chain-based auctions perform well in comparison with other schemes, especially as arrival intensity falls and agent valuations become more volatile

Crowd-sourcing with uncertain quality - an auction approach

This article addresses two important issues in crowd-sourcing: ex ante uncertainty about the quality and cost of different workers and strategic behaviour. We present a novel multi-dimensional auction that incentivises the workers to make partial enquiry into the task and to honestly report quality-cost estimates based on which the crowd-sourcer can choose the worker that offers the best value for money. The mechanism extends second score auction design to settings where the quality is uncertain and it provides incentives to both collect information and deliver desired qualities