North Sea oil and genuine saving in the Scottish economy

The World Bank has published estimates of sustainability of consumption paths by adjusting saving rates to take account of the depletion of non-renewable resources. During the period of North Sea oil production Scotland has been in a fiscal union with the rest of the UK. The present paper adjusts the World Bank data to produce separate genuine saving estimates for Scotland and the rest of the UK for 1970-2009, based on a ‘derivation’ principle for oil revenues. The calculations indicate that Scotland has had a negative genuine saving rate for most of the period of exploitation of North Sea oil resources, with genuine saving being positive in the rest of the UK during this period

Hysteresis and economics - taking the economic past into account

The goal of this article is to discuss the rationale underlying the application of hysteresis to economic models. In particular, we explain why many aspects of real economic systems are hysteretic is plausible. The aim is to be explicit about the difficulties encountered when trying to incorporate hysteretic effects into models that can be validated and then used as possible tools for macroeconomic control. The growing appreciation of the ways that memory effects influence the functioning of economic systems is a significant advance in economic thought and, by removing distortions that result from oversimplifying specifications of input-output relations in economics, has the potential to narrow the gap between economic modeling and economic reality

Unemployment: natural rate epicycles or hysteresis?

This paper argues that the natural rate of unemployment hypothesis, in which equilibrium unemployment is determined by “structural” variables alone, is wrong: it is both implausible and inconsistent with the evidence. Instead, equilibrium unemployment is haunted by hysteresis. The curious history of the natural rate hypothesis is considered, curious because the authors of the hypothesis thought hysteresis to be relevant. The various methods that have been used to model hysteresis in economic systems are outlined, including the Preisach model with its selective, erasable memory properties. The evidence regarding hysteresis effects on output and unemployment is then reviewed. The implications for macroeconomic policy, and for the macroeconomics profession, are discussed

Memory of recessions.

This paper reviews the evidence on the effects of recessions on potential output. In contrast to the assumption in mainstream macroeconomic models that economic fluctuations do not change potential output paths, the evidence is that they do in the case of recessions. A model is proposed to explain this phenomenon, based on an analogy with water flows inporous media. Because of the discrete adjustments made by heterogeneous economic agents in such a world, potential output displays hysteresis with regard to aggregate demand shocks, and thus retains a memory of the shocks associated with recessions.Recessions, Permanent Effects, Hydraulic Keynesianism, Porous Media, Hysteresis.

Hysteresis and unemployment : a preliminary investigation

This paper points out what hysteresis is using a simple model of market entry and exit. A procedure for calculating hysteresis indices for economic time series is outlined. Some preliminary results are presented to assess the explanatory power of hysteresis variables with regard to the equilibrium rate of unemployment in the UK. We find that both natural and "unnatural" variables enter a cointegrating vector for UK unemployment 1959-1996. The natural variable is the replacement ratio. The 'unnatural' variables are the hysteresis index of the exchange rate; and hysteresis indices for the real oil price and the real interest rate

Scattering of a Baseball by a Bat

A ball can be hit faster if it is projected without spin but it can be hit farther if it is projected with backspin. Measurements are presented in this paper of the tradeoff between speed and spin for a baseball impacting a baseball bat. The results are inconsistent with a collision model in which the ball rolls off the bat and instead imply tangential compliance in the ball, the bat, or both. If the results are extrapolated to the higher speeds that are typical of the game of baseball, they suggest that a curveball can be hit with greater backspin than a fastball, but by an amount that is less than would be the case in the absence of tangential compliance.Comment: Accepted for publication in American Journal of Physic

Hysteresis in the fundamentals of macroeconomics.

Two fundamental problems in economic analysis concern the determination of aggregate output, and the determination of market prices and quantities. The way economic adjustments are made at the micro level suggests that the history of shocks to the economic environment matters. This paper presents tractable approach for introducing hysteresis into models of how aggregate output and market prices and quantities are determined.Hysteresis, Aggregate Output, Market Supply and Demand

Periodic Sequences of Arbitrage: A Tale of Four Currencies

This paper investigates arbitrage chains involving four currencies and four foreign exchange trader-arbitrageurs. In contrast with the three-currency case, we find that arbitrage operations when four currencies are present may appear periodic in nature, and not involve smooth convergence to a "balanced" ensemble of exchange rates in which the law of one price holds. The goal of this article is to understand some interesting features of sequences of arbitrage operations, features which might well be relevant in other contexts in finance and economics.Comment: 35 pages, 48 bibliography references, submitted to Metroeconomic

Periodic Sequences of Arbitrage: A Tale of Four Currencies

This paper investigates arbitrage chains involving four currencies and four foreign ex-change trader-arbitrageurs. In contrast with the three-currency case, we find that arbitrage operations when four currencies are present may appear periodic in nature, and not involve smooth convergence to a "balanced" ensemble of exchange rates in which the law of one price holds. The goal of this article is to understand some interesting features of sequences of arbitrage operations, features which might well be relevant in other contexts in finance and economics.Limits to arbitrage, Four currencies, Recurrent sequences, Asynchronous systems

An Appraisal of Friedman's Positively Sloped Phillips Curve Conjecture

In this paper we ask what happens in the medium-term interregnum between the domain of the short run Phillips curve and that of the long run Phillips curve. In this interregnum inflation is anticipated but has real effects on the natural rate of unemployment, according to Friedman's conjecture. We discuss the new classical and hysteresis alternatives to Friedman's conjecture, and some of the methodological issues involved in appraising the conjecture. A simple model, and some data, are employed in this task