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.

Value-oriented impact assessment: the economics of a new approach to impact assessment

Environmental Impact Assessment has gained a prominent position as a tool to evaluate the environmental effects of economic activities. However, all approaches proposed so far use a burden-oriented logic. They concentrate on the different environmental impacts in order to ascertain the overall environmental damage caused by economic activity. This paper argues that such a burden-oriented view is (a) hampered by a series of methodological shortcomings which hinders its widespread use in practice; and (b) is analytically incomplete. The paper proposes a value-oriented approach to impact assessment. For this purpose an economic analysis of the optimal use of environmental and social resources is conducted from both a burden-oriented and a value-oriented standpoint. The basic logic of a value-oriented impact assessment is explained, as well as the resulting economic conditions for an optimal use of resources. In addition, it is shown that value- and burden-oriented approaches are complementary to achieve optimality. Finally, the paper discusses the conditions under which the use of burden- or value-oriented impact assessments is appropriate, respectively.

Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke

This exploratory study was undertaken to investigate the mechanisms that contributed to improvements in upper limb function following a novel training program. Surface electromyography (EMG) was used to examine training-induced changes in the pattern of triceps and biceps activation during reaching tasks in stroke survivors with severe paresis in the chronic stage of recovery. The EMG data were obtained in the context of a single blind randomised clinical trial conducted with 42 stroke survivors with minimal upper limb muscle activity and who were more than 6 months post-stroke. Of the 33 participants who completed the study, 10 received training of reaching using a non-robotic upper limb training device, the SMART Arm, with EMG triggered functional electrical stimulation (EMG-stim), 13 received training of reaching using the SMART Arm alone, and 10 received no intervention. Each intervention group engaged in 12 1-h training sessions over a 4-week period. Clinical and laboratory measures of upper limb function were administered prior to training (0 weeks), at completion (4 weeks) and 2 months (12 weeks) after training. The primary outcome measure was 'upper arm function' which is Item 6 of the Motor Assessment Scale (MAS). Laboratory measures consisted of two multijoint reaching tasks to assess 'maximum isometric force' and 'maximum distance reached'. Surface EMG was used to monitor triceps brachii and biceps brachii during the two reaching tasks. To provide a comparison with normal values, seven healthy adults were tested on one of the reaching tasks according to the same procedure. Study findings demonstrated a statistically significant improvement in upper limb function for stroke participants in the two training groups compared to those who received no training however no difference was found between the two training groups. For the reaching tasks, all stroke participants, when compared to normal healthy adults, exhibited lower triceps and biceps activation and a lower ratio of triceps to biceps activation. Following training, stroke participants demonstrated increased triceps activation and an increased ratio of triceps to biceps activation for the task that was trained. Better performance was associated with greater triceps activation and a higher ratio of triceps to biceps activation. The findings suggest that increased activation of triceps as an agonist and an improved coordination between triceps and biceps could have mediated the observed changes in arm function. The changes in EMG activity were small relative to the changes in arm function indicating that factors, such as the contribution of other muscles of reaching, may also be implicated.