The ‘Urban Age’ in Question

Foreboding declarations about contemporary urban trends pervade early twenty‐first century academic, political and journalistic discourse. Among the most widely recited is the claim that we now live in an ‘urban age’ because, for the first time in human history, more than half the world's population today purportedly lives within cities. Across otherwise diverse discursive, ideological and locational contexts, the urban age thesis has become a form of doxic common sense around which questions regarding the contemporary global urban condition are framed. This article argues that, despite its long history and its increasingly widespread influence, the urban age thesis is a flawed basis on which to conceptualize world urbanization patterns: it is empirically untenable (a statistical artifact) and theoretically incoherent (a chaotic conception). This critique is framed against the background of postwar attempts to measure the world's urban population, the main methodological and theoretical conundrums of which remain fundamentally unresolved in early twenty‐first century urban age discourse. The article concludes by outlining a series of methodological perspectives for an alternative understanding of the contemporary global urban condition.     

Bayesian model averaging and identification of structural breaks in time series

Bayesian Model Averaging (BMA) is used for testing for multiple break points in univariate series using conjugate normal-gamma priors. This approach can test for the number of structural breaks and produce posterior probabilities for a break at each point in time. Results are averaged over specifications including: stationary; stationary around trend and unit root models, each containing different types and number of breaks and different lag lengths. The procedures are used to test for structural breaks on 14 annual macroeconomic series and 11 natural resource price series. The results indicate that there are structural breaks in all of the natural resource series and most of the macroeconomic series. Many of the series had multiple breaks. Our findings regarding the existence of unit roots, having allowed for structural breaks in the data, are largely consistent with previous work.     

The power of asymmetric unit root tests under threshold and consistent-threshold estimation

The asymmetric unit root tests of Enders and Granger (Journal of Business and Economic Statistics, 16, 304–11, 1998) are examined using consistent threshold estimation and the original two-step procedure. In contrast to earlier studies, the ability of the tests to jointly reject the unit root and symmetry hypotheses is examined, thus permitting a fuller analysis of the tests' properties. Whilst the threshold autoregressive test is found to have little power in either its consistent or original forms, the consistent momentum-threshold autoregressive test is found to exhibit high power against a range of plausible alternatives when using newly derived critical values.     

Delay and Settlement in Litigation

Delay in litigation is a policy concern in many jurisdictions. Little evidence is available on the causes of such delay, however. We present a version of Spier's (1992) bargaining model of litigation and derive directly a functional form for the conditional probability of case settlement. We then estimate this and test predictions about the effects of legal costs and uncertainty over damages and liability on the conditional probability of settlement, using data from negligence claims against several NHS Trusts. Our results provide a direct test of the model and shed light on the causes of settlement delay in England.     

Perpetual youth and endogenous labor supply: A problem and a possible solution

In the “perpetual youth” overlapping-generations model of Blanchard and Yaari, if leisure is a “normal” good then some agents will have negative labor supply. We suggest a solution to this problem by using a modified version of Greenwood, Hercowitz and Huffman’s utility function. The modification incorporates real money balances, so that the model may be used to analyze monetary as well as fiscal policy. In a Walrasian version of the economy, we show that increased government debt and increased government spending raise the interest rate and lower output, while an open-market operation to increase the money supply lowers the interest rate and raises output.     

Do Teachers Matter? Measuring the Variation in Teacher Effectiveness in England*

Using a unique primary dataset for the UK, we estimate the effect of individual teachers on student outcomes, and the variability in teacher quality. This links 7,305 pupils to the individual teachers who taught them, in each of their compulsory subjects in the high‐stakes exams at age 16. We use point‐in‐time fixed effects and prior attainment to control for pupil heterogeneity. We find considerable variability in teacher effectiveness, a little higher than the estimates found in the few US studies. We also corroborate recent findings that observed teachers’ characteristics explain very little of the differences in estimated teacher effectiveness.     

“Greening” the marketing mix: do firms do it and does it pay off?

Growing concern about the sustainability of the natural environment is rapidly transforming the competitive landscape and forcing companies to explore the costs and benefits of “greening” their marketing mix. We develop and test a theoretical model that predicts (1) the role of green marketing programs in influencing firm performance, (2) the impact of slack resources and top management risk aversion on the deployment of such programs, and (3) the conditioning effects that underpin these relationships. Our analyses show that green marketing programs are being implemented by firms, and we find evidence of significant performance payoffs. Specifically the results indicate that green product and distribution programs positively affect firms’ product-market performance, while green pricing and promotion practices are directly positively related to firms’ return on assets. In addition, industry-level environmental reputation moderates the links between green marketing program components and firms’ product-market and financial performance. Finally, we find that slack resources and top management risk aversion are independently conducive to the adoption of green marketing programs—but operate as substitutes for each other.     

Endogenous R&D networks when labour unions have preferences over wages and employment

We develop a model to analyse the pattern of R&D network formation when unions have relative preferences over wages and employment. Within a three-firm industry, we show that when the unions place a low weight on wages and technological spillovers are low, a partial R&D network that includes two firms but excludes the third emerges in equilibrium. In contrast, when the unions care a lot about wages, a complete R&D network that includes all firms emerges. For all other intermediate levels of union preferences over wages, there is no strong stable equilibrium network. Empirical implications emerge from these findings, which are also discussed.     

Physical and Economic Consequences of Sea-Level Rise: A Coupled GIS and CGE Analysis Under Uncertainties

This paper develops a modelling framework that links GEMINI-E3, a multi-regional, multi-sectoral computable general equilibrium model with a cost-benefit analysis approach at local level using geographical information system tools to assess the physical and economic consequences of sea-level rise (SLR) in the twenty first century. A set of future scenarios is developed spanning the uncertainties related to global warming, the parameters of semi-empirical SLR estimates, and coastal developments (cropland, urban areas and population). The importance of incorporating uncertainties regarding coastal development is highlighted. The simulation results suggest that the potential development of future coastal areas is a greater source of uncertainty than the parameters of SLR itself in terms of the economic consequences of SLR. At global level, the economic impact of SLR could be significant when loss of productive land along with loss of capital and forced displacement of populations are considered. Furthermore, highly urbanised and densely populated coastal areas of South East Asia, Australia and New Zealand are likely to suffer significantly if no protective measures are taken. Hence, it is suggested that coastal areas needs to be protected to ameliorate the overall welfare cost across various regions.