Sketching: Friend or Foe to the Novice Designer?

Previous research by one of the authors showed that novice designers do not use sketching as a way to generate, develop and communicate design proposals, but move immediately to three-dimensional modelling. Neither do they generate multiple solutions. The follow-up study described here addressed the questions: Does teaching two-dimensional modelling enable Grade 7 pupils to better express their ideas and organize their thoughts? What role does discussion play in pupils' attempts to generate a design proposal? Does the use of contextualising items make a difference to pupils' success with designing? Eight Grade 7 pupils were drawn from each of two classes. One class had received instruction in sketching; the other served as a control group. Each group of eight pupils was divided into single-sex dyads. The eight dyads were videotaped while producing a solution to a common design brief. Analysis of the data has provided insights into the effects of instruction on the proposals produced by pupils. Additionally, their ability to generate, develop and communicate design ideas is enhanced by both the dynamic relationship between pupils' talk and 3D modelling and the way the task is contextualised. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evidence on nonlinear error correction in money demand: the case of Taiwan

This paper proposes a nonlinear error-correction model based upon smooth transition regression methodology. The model is specified such that the short-run adjustment toward long-run equilibrium is nonlinear and that the error correction is a smooth function of long-run deviation. Empirical results obtained from estimating M2 money demand in Taiwan support the hypothesis of a nonlinear error-correction process and provide better interpretation of change in the demand for money.     

Doha development agenda: implications for the US and world cotton markets

This study analyzed two scenarios that considered a reduction of the US aggregate measure of supports (AMS) payments by 60% over a five-year period. In the first scenario, which considered a unilateral action by the US, the targeted AMS payments reduction would require a 12% cut in the US target price and an 8% cut in the loan rate. This would lead to a 3% decline in US cotton production, a 3% rise in world cotton price, and a 26% decline in US cotton net farm income at the end of the implementation period. The second scenario analyzed the case in which the US AMS payments reduction is concomitant with multilateral tariff and subsidy eliminations from the rest of the world. Under this scenario, fewer cuts in the US loan rate and target price (i.e. 9 and 4%) were required to achieve the 60% AMS reduction because of market liberalization from the from the rest of the world. However, US cotton producers' net farm income still declined by 18%.     

A simple closed-form approximation for the cumulative distribution function of the composite error of stochastic frontier models

This paper derives an analytic closed-form formula for the cumulative distribution function (cdf) of the composite error of the stochastic frontier analysis (SFA) model. Since the presence of a cdf is frequently encountered in the likelihood-based analysis with limited-dependent and qualitative variables as elegantly shown in the classic book of Maddala (Limited-dependent and qualitative variables in econometrics. Cambridge University Press, Cambridge, 1983), the proposed methodology is useful in the framework of the stochastic frontier analysis. We apply the formula to the maximum likelihood estimation of the SFA models with a censored dependent variable. The simulations show that the finite sample performance of the maximum likelihood estimator of the censored SFA model is very promising. A simple empirical example on the modeling of reservation wage in Taiwan is illustrated as a potential application of the censored SFA.     

Tracing the Origins of Personalist Economics to Aristotle and Aquinas

Personalist Economics has identified a central problem in Neoclassical Economics that originates in its representation of the economic agent as homo economicus and its grounding in individualism. Both flaws are directly addressed by Personalist Economics that has a different perspective on human nature as set forth in Personalism. Our remarks are presented in three sections. In the first section we address why individualism is an unsatisfactory philosophical foundation for modern economic theory. In the second section we trace the origins of Personalist Economics to Aristotle and Aquinas. While others, such as Heinrich Pesch and Joseph Schumpeter, played important roles in the evolution of Personalist Economics, here our efforts are restricted to the contributions of Aristotle and Aquinas. In the third section we explore how, in terms of 18 tenets, Personalist Economics and a Personalist economy differ from Mainstream Economics and the individualistic market economy.     

A new approach to estimating the metafrontier production function based on a stochastic frontier framework

This paper proposes a new two-step stochastic frontier approach to estimate technical efficiency (TE) scores for firms in different groups adopting distinct technologies. Analogous to Battese et al. (J Prod Anal 21:91–103, 2004), the metafrontier production function allows for calculating comparable TE measures, which can be decomposed into group specific TE measures and technology gap ratios. The proposed approach differs from Battese et al. (J Prod Anal 21:91–103, 2004) and O’Donnell et al. (Empir Econ 34:231–255, 2008) mainly in the second step, where a stochastic frontier analysis model is formulated and applied to obtain the estimates of the metafrontier, instead of relying on programming techniques. The so-derived estimators have the desirable statistical properties and enable the statistical inferences to be drawn. While the within-group variation in firms’ technical efficiencies is frequently assumed to be associated with firm-specific exogenous variables, the between-group variation in technology gaps can be specified as a function of some exogenous variables to take account of group-specific environmental differences. Two empirical applications are illustrated and the results appear to support the use of our model.     

The Value of Plains Cotton Cooperative Association

The Value of Plains Cotton Cooperative Association is a teaching case that allows students to consider the cooperative business model and the impact of this unique form of organization in agriculture. The Plains Cotton Cooperative Association (PCCA) , a highly successful, innovative, and dominant cotton cooperative, is considered in this case.
The general question is whether the cooperative form of organization is viable and relevant in the face of intensifying economic competition. Cotton producers and long-time co-op members must decide if they will remain loyal to the cooperative in light of recent negative publicity and disappointing returns from its marketing operations.     

Open fields, risk, and land divisibility

Why were open fields pervasive in the middle ages? Our findings support the general contention that behavior towards risk explains the persistence of open fields, but we reject the mechanism of diversification via scattered landholdings. Simulation analysis is used to estimate the relative efficiency of alternative forms of insurance available to peasant households. We find that, for the vast majority of peasants, self-insurance through land accumulation was a superior risk management/wealth accumulation strategy, but only if land could be transacted in small parcels. Scattering existed because it transformed land into a divisible savings instrument.