Structure and Change: Douglass North's Economics

Douglass North is a pivotal figure in the development of the 'new' economic history as well as the 'new' institutional economics. However, the relationship between these two aspects of his thinking remains undeveloped in previous critical assessments of North's work. The relationship is clarified here. The evidence presented indicates that three distinct phases can be distinguished in his writings between the 1950s and the 2000s. The paper relates these changing views to the shifting mainstream within economics and the effects that this shift has in turn had on economic history research. Economic history has adapted to economic research by abandoning some practices associated with the earlier cliometric literature. Furthermore, North is unique to the extent that his recent writings represent something of a convergence with 'old' institutionalism. © 2010 Taylor & Francis.

Testing the role of expansion in the prospective control of locomotion

The constant bearing angle (CBA) strategy is a prospective strategy that permits the interception of moving objects. The purpose of the present study is to test this strategy. Participants were asked to walk through a virtual environment and to change, if necessary, their walking speed so as to intercept approaching targets. The targets followed either a rectilinear or a curvilinear trajectory and target size was manipulated both within trials (target size was gradually changed during the trial in order to bias expansion) and between trials (targets of different sizes were used). The curvature manipulation had a large effect on the kinematics of walking, which is in agreement with the CBA strategy. The target size manipulations also affected the kinematics of walking. Although these effects of target size are not predicted by the CBA strategy, quantitative comparisons of observed kinematics and the kinematics predicted by the CBA strategy showed good fits. Furthermore, predictions based on the CBA strategy were deemed superior to predictions based on a required velocity (V-REQ) model. The role of target size and expansion in the prospective control of walking is discussed.