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

/pdf/theory-and-time-series-estimation-of-the-quadratic-luwga7ndlf.pdf

Theory and Time Series Estimation of the Quadratic Expenditure System

http://sites.psu.edu/scottcolby/wp-content/uploads/sites/13885/2014/07/Diewert1988_A-Normalized-Quadratic-Semiflexible-Functional-Form.pdf

A normalized quadratic semiflexible functional form

We introduce a procedure for imposing curvature conditions locally in a class of flexible demand systems. Aside from the simplicity of the procedure, a major advantage is that flexibility is maintained. We illustrate the technique by estimating three flexible demand systems—the normalized quadratic, the almost ideal, and the linear translog—using highly aggregated Canadian data for the period 1947 through 1993. When curvature is not imposed, these demand systems violate the appropriate curvature conditions at every data point. When curvature is imposed, curvature conditions are satisfied not only at the point of imposition but at every data point.

A Simple Method for Imposing Local Curvature in Some Flexible Consumer-Demand Systems

Sample Selectivity and the Estimation of Labor Supply Functions

Empirically estimated demand systems frequently fail to satisfy the appropriate theoretical curvature conditions. We propose and estimate two demand systems for which these conditions can be imposed globally; the first is derived from a normalized quadratic reciprocal indirect utility function and the second is derived from a normalized quadratic expenditure function. The former is flexible if there are no restrictions on its free parameters, but loses flexibility if the curvature conditions need to be imposed. The latter is flexible, in the class of functions satisfying local money metric scaling, even if the curvature conditions need to be imposed.

Terence Wales

Papers

Theory and Time Series Estimation of the Quadratic Expenditure System

A normalized quadratic semiflexible functional form

A Simple Method for Imposing Local Curvature in Some Flexible Consumer-Demand Systems

Sample Selectivity and the Estimation of Labor Supply Functions

Normalized Quadratic Systems of Consumer Demand Functions