Many teaching practices implicitly assume that conceptual knowledge can be abstracted from the situations in which it is learned and used. This article argues that this assumption inevitably limits the effectiveness of such practices. Drawing on recent research into cognition as it is manifest in everyday activity, the authors argue that knowledge is situated, being in part a product of the activity, context, and culture in which it is developed and used. They discuss how this view of knowledge affects our understanding of learning, and they note that conventional schooling too often ignores the influence of school culture on what is learned in school. As an alternative to conventional practices, they propose cognitive apprenticeship (Collins, Brown, & Newman, in press), which honors the situated nature of knowledge. They examine two examples of mathematics instruction that exhibit certain key features of this approach to teaching.

/pdf/situated-cognition-and-the-culture-of-learning-3pg6ch1r4f.pdf

Situated Cognition and the Culture of Learning

https://steadystate.org/wp-content/uploads/Stern_KuznetsCurve.pdf

The Rise and Fall of the Environmental Kuznets Curve

Econometricians would like to project the image of agricultural experimenters who divide a farm into a set of smaller plots of land and who select randomly the level of fertilizer to be used on each plot. If some plots are assigned a certain amount of fertilizer while others are assigned none, then the difference between the mean yield of the fertilized plots and the mean yield of the unfertilized plots is a measure of the effect of fertilizer on agricultural yields. The econometrician's humble job is only to determine if that difference is large enough to suggest a real effect of fertilizer, or is so small that it is more likely due to random variation. This image of the applied econometrician's art is grossly misleading. I would like to suggest a more accurate one. The applied econometrician is like a farmer who notices that the yield is somewhat higher under trees where birds roost, and he uses this as evidence that bird droppings increase yields. However, when he presents this finding at the annual meeting of the American Ecological Association, another farmer in the audience objects that he used the same data but came up with the conclusion that moderate amounts of shade increase yields. A bright chap in the back of the room then observes that these two hypotheses are indistinguishable, given the available data. He mentions the phrase "identification problem," which, though no one knows quite what he means, is said with such authority that it is totally convincing. The meeting reconvenes in the halls and in the bars, with heated discussion

https://www.pc.gov.au/inquiries/completed/pig-safeguards-2008/submissions/ar103_minter_ellison/subAR103_attachment.pdf

Let's Take the Con Out of Econometrics

Data augmentation and Gibbs sampling are two closely related, sampling-based approaches to the calculation of posterior moments. The fact that each produces a sample whose constituents are neither independent nor identically distributed complicates the assessment of convergence and numerical accuracy of the approximations to the expected value of functions of interest under the posterior. In this paper methods from spectral analysis are used to evaluate numerical accuracy formally and construct diagnostics for convergence. These methods are illustrated in the normal linear model with informative priors, and in the Tobit-censored regression model.

Evaluating the accuracy of sampling-based approaches to the calculation of posterior moments

Marriage and household decision-making: a bargaining analysis

In this paper, the authors propose and estimate a system of producer output supply and input demand functions that generalizes the standard normalized quadratic form. The generalization adds either linear or quadratic splines in a time (or technical change) variable, yet retains the main attractive property of the normalized quadratic, which is that it can provide a local second order approximation while maintaining the correct curvature globally. However, the generalization has additional desirable approximation properties with respect to the splined variable and, thus, permits a more flexible treatment of technical change than is provided by standard flexible functional forms. Copyright 1992 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

Quadratic Spline Models for Producer's Supply and Demand Functions

Previous attempts to estimate labor supply functions based upon the constrained maximization of a utility function with leisure and income as arguments have assumed that all time not spent at work on the job is leisure time. In this paper we formulate a model of a household in which time is allocated between work on the job, leisure, and housework, where leisure is defined to be net of time spent on housework. The model is estimated under two alternative stochastic specifications and the results compared to those obtained (i) assuming that housework time is exogenous and (ii) assuming that housework time is part of leisure time.

Estimation of the Allocation of Time for Work, Leisure, and Housework

In this paper, we introduce three flexible consumer demand systems in which expenditures on goods are quadratic functions of income. We view these alternatives as to the demand systems used heretofore in the empirical modeling of rank-three demands, namely those in which expenditure shares are quadratic functions of the logarithm of income. Curvature conditions required by theory can be imposed locally during the estimation for each, and a semiflexible version can be estimated. For illustrative purposes, we estimate various forms of two of the systems using Canadian data on seven categories of goods for the period 1947 to 1995.

Terence Wales

Papers

Quadratic Spline Models for Producer's Supply and Demand Functions

Estimation of the Allocation of Time for Work, Leisure, and Housework

Flexible and Semiflexible Consumer Demands with Quadratic Engel Curves

The CES-Translog: Specification and Estimation of a New Cost Function

Flexible functional forms and tests of homogeneous separability