Living with Global Imbalances

macroeconomics, Global Imbalances

Dealing with the Trade Deficit in a Floating Rate System

macroeconomics, trade deficit, floating rate system

Is the U.S. Current Account Deficit Sustainable? Will It Be Sustained?

U.S. Current Account Deficit, Sustainable, Deficit, U.S. Current Account, macroeconomics

Resource Needs Revisited

macroeconomics, resource needs

A Note on Deregulation of Natural Gas Prices

macroeconomics, natural gas, pricing, deregulation

Living with Global Imbalances: A Contrarian View

Three propositions have become conventional wisdom in Washington and elsewhere: Americans save too little. The US current account deficit is thus unsustainably large. The Chinese currency must appreciate significantly to bring the global economy into sustainable balance. All these separate but related propositions are highly questionable, the author says. He suggests that Americans save quite enough for future generations, that the startlingly large US current account deficit is not only sustainable but a natural feature of today's highly globalized economy, and that a revaluation of the Chinese currency, far from alleviating global imbalances, would run the risk of precipitating a financial crisis.

Inhibition and young children's performance on the Tower of London task

Young children, when performing problem solving tasks, show a tendency to break task rules and produce incomplete solutions. We propose that this tendency can be explained by understanding problem solving within the context of the development of “executive functions” – general cognitive control functions, which serve to regulate the operation of the cognitive system. This proposal is supported by the construction of two computational models that simulate separately the performance of 3–4 year old and 5–6 year old children on the Tower of London planning task. We seek in particular to capture the emerging role of inhibition in the older group. The basic framework within which the models are developed is derived from Fox and Das’ Domino model [Fox, J., & Das, S. (2000). Safe and sound: Artificial intelligence in hazardous applications. Cambridge, MA: MIT Press] and Norman and Shallice’s [Norman, D.A., & Shallice, T. (1986). Attention to action: Willed and automatic control of behaviour. In R. Davidson, G. Schwartz, & D. Shapiro (Eds.), Consciousness and Self Regulation (Vol. 4). New York: Plenum] theory of willed and automatic action. Two strategies and a simple perceptual bias are implemented within the models and comparisons between model and child performance reveal a good fit for the key dependent measures (number of rule breaks and percentage of incomplete solutions) of the two groups

Mechanisms for the generation and regulation of sequential behaviour

A critical aspect of much human behaviour is the generation and regulation of sequential activities. Such behaviour is seen in both naturalistic settings such as routine action and language production and laboratory tasks such as serial recall and many reaction time experiments. There are a variety of computational mechanisms that may support the generation and regulation of sequential behaviours, ranging from those underlying Turing machines to those employed by recurrent connectionist networks. This paper surveys a range of such mechanisms, together with a range of empirical phenomena related to human sequential behaviour. It is argued that the empirical phenomena pose difficulties for most sequencing mechanisms, but that converging evidence from behavioural flexibility, error data arising from when the system is stressed or when it is damaged following brain injury, and between-trial effects in reaction time tasks, point to a hybrid symbolic activation-based mechanism for the generation and regulation of sequential behaviour. Some implications of this view for the nature of mental computation are highlighted

Order and disorder in everyday action: the roles of contention scheduling and supervisory attention

This paper describes the contention scheduling/supervisory attentional system approach to action selection and uses this account to structure a survey of current theories of the control of action. The focus is on how such theories account for the types of error produced by some patients with frontal and/or left temporoparietal damage when attempting everyday tasks. Four issues, concerning both the theories and their accounts of everyday action breakdown, emerge: first, whether multiple control systems, each capable of controlling action in different situations, exist; second, whether different forms of damage at the neural level result in conceptually distinct disorders; third, whether semantic/conceptual knowledge of objects and actions can be dissociated from control mechanisms, and if so what computational principles govern sequential control; and fourth, whether disorders of everyday action should be attributed to a loss of semantic/conceptual knowledge, a malfunction of control, or some combination of the two

Cognitive control in the generation of random sequences: a computational study of secondary task effects

Cognitive control processes, such as those involved in response inhibition or task switching, have been the focus of much recent research. Few studies, however, have considered how such processes work together in tasks that require multiple control processes. This paper reports a computational study of random sequence generation and the cognitive control processes involved therein. The task, which is argued to involve multiple control processes, produces several dependent measures. These measures are held to be differentially dependent on the differential efficacy of the various underlying control processes. Initial simulations demonstrate that the model is capable of reproducing subject performance on the basic task. Additional simulations explore differential interference effects of different secondary tasks (held to interfere with different control processes) on the different random generation dependent measures. The work illustrates how the putative control processes may interact in the production of successive responses during the random generation task