Nonlinear and Complex Dynamics in Economics

This paper is an up-to-date survey of the state-of-the-art in dynamical systems theory relevant to high levels of dynamical complexity, characterizing chaos and near chaos, as commonly found in the physical sciences. The paper also surveys applications in economics and �finance. This survey does not include bifurcation analyses at lower levels of dynamical complexity, such as Hopf and transcritical bifurcations, which arise closer to the stable region of the parameter space. We discuss the geometric approach (based on the theory of differential/difference equations) to dynamical systems and make the basic notions of complexity, chaos, and other related concepts precise, having in mind their (actual or potential) applications to economically motivated questions. We also introduce specifi�c applications in microeconomics, macroeconomics, and �finance, and discuss the policy relevancy of chaos

Consumer preferences and demand systems

This paper is an up-to-date survey of the state-of-the-art in consumer demand modelling. We review and evaluate advances in a number of related areas, including different approaches to empirical demand analysis, such as the differential approach, the locally �flexible functional forms approach, the semi-nonparametric approach, and a nonparametric approach. We also address estimation issues, including sampling theoretic and Bayesian estimation methods, and discuss the limitations of the currently common approaches. We also highlight the challenge inherent in achieving economic regularity, for consistency with the assumptions of the underlying neoclassical economic theory, as well as econometric regularity, when variables are nonstationary.Representative consumer; Engel curves; rank; flexible functional forms; parametric tests; nonparametric tests; theoretical regularity

The Differential Approach to Demand Analysis and the Rotterdam Model

This paper presents the differential approach to applied demand analysis. The demand systems of this approach are general, having coefficients which are not necessarily constant. We consider the Rotterdam parameterization of differential demand systems and derive the absolute and relative price versions of the Rotterdam model, due to Theil (1965) and Barten (1966). We address estimation issues and point out that, unlike most parametric and semi-nonparametric demand systems, the Rotterdam model is econometrically regular.differential demand systems; theoretical regularity; econometric regularity

Measuring Consumer Preferences and Estimating Demand Systems

This chapter is an up-to-date survey of the state-of-the art in consumer demand analysis. We review (and evaluate) advances in a number of related areas, in the spirit of the recent survey paper by Barnett and Serletis (2008). In doing so, we only deal with consumer choice in a static framework, ignoring a number of important issues, such as, for example, the effects of demographic or other variables that affect demand, welfare comparisons across households (equivalence scales), and the many issues concerning aggregation across consumers.demand systems; consumer preferences, theoretical regularity

Nonlinear and Complex Dynamics in Real Systems

This is the publisher's version, also available electronically from http://www.degruyter.com/view/j/ijnsns.2006.7.2/ijnsns.2006.7.2.191/ijnsns.2006.7.2.191.xml?format=INT.In this article we provide a review of the literature with respect to fluctuations in real systems and chaos. In doing so, we contrast the order and organization hypothesis of real systems to nonlinear chaotic dynamics and discuss some techniques used in distinguishing between stochastic and deterministic behavior. Moreover, we look at the issue of where and when the ideas of chaos could profitably be applied to real systems

Measuring Consumer Preferences and Estimating Demand Systems

This chapter is an up-to-date survey of the state-of-the art in consumer demand analysis. We review (and evaluate) advances in a number of related areas, in the spirit of the recent survey paper by Barnett and Serletis (2008). In doing so, we only deal with consumer choice in a static framework, ignoring a number of important issues, such as, for example, the effects of demographic or other variables that affect demand, welfare comparisons across households (equivalence scales), and the many issues concerning aggregation across consumers

The Differential Approach to Demand Analysis and the Rotterdam Model

This paper presents the differential approach to applied demand analysis. The demand systems of this approach are general, having coefficients which are not necessarily constant. We consider the Rotterdam parameterization of differential demand systems and derive the absolute and relative price versions of the Rotterdam model, due to Theil (1965) and Barten (1966). We address estimation issues and point out that, unlike most parametric and semi-nonparametric demand systems, the Rotterdam model is econometrically regular

Measuring Consumer Preferences and Estimating Demand Systems

This chapter is an up-to-date survey of the state-of-the art in consumer demand analysis. We review (and evaluate) advances in a number of related areas, in the spirit of the recent survey paper by Barnett and Serletis (2008). In doing so, we only deal with consumer choice in a static framework, ignoring a number of important issues, such as, for example, the effects of demographic or other variables that affect demand, welfare comparisons across households (equivalence scales), and the many issues concerning aggregation across consumers

Operating theatre related syncope in medical students: a cross sectional study

<p>Abstract</p> <p>Background</p> <p>Observing surgical procedures is a beneficial educational experience for medical students during their surgical placements. Anecdotal evidence suggests that operating theatre related syncope may have detrimental effects on students' views of this. Our study examines the frequency and causes of such syncope, together with effects on career intentions, and practical steps to avoid its occurrence.</p> <p>Methods</p> <p>All penultimate and final year students at a large UK medical school were surveyed using the University IT system supplemented by personal approach. A 20-item anonymous questionnaire was distributed and results were analysed using the Statistical Package for Social Sciences, version 15.0 (Chicago, Illinois, USA).</p> <p>Results</p> <p>Of the 630 clinical students surveyed, 77 responded with details of at least one near or actual operating theatre syncope (12%). A statistically significant gender difference existed for syncopal/near-syncopal episodes (male 12%; female 88%), p < 0.05. Twenty-two percent of those affected were graduate entry medical course students with the remaining 78% undergraduate. Mean age was 23-years (range 20 – 45). Of the 77 reactors, 44 (57%) reported an intention to pursue a surgical career. Of this group, 7 (9%) reported being discouraged by syncopal episodes in the operating theatre. The most prevalent contributory factors were reported as hot temperature (n = 61, 79%), prolonged standing (n = 56, 73%), wearing a surgical mask (n = 36, 47%) and the smell of diathermy (n = 18, 23%). The most frequently reported measures that students found helpful in reducing the occurrence of syncopal episodes were eating and drinking prior to attending theatre (n = 47, 61%), and moving their legs whilst standing (n = 14, 18%).</p> <p>Conclusion</p> <p>Our study shows that operating theatre related syncope among medical students is common, and we establish useful risk factors and practical steps that have been used to prevent its occurrence. Our study also highlights the detrimental effect of this on the career intentions of medical students interested in surgery. Based on these findings, we recommend that dedicated time should be set aside in surgical teaching to address this issue prior to students attending the operating theatre.</p