On invariant parametric covariance families

Summary In this note we characterize all linear transformations of random vectors which are invariant for a given parametric covariance family. Two one-dimensional covariance families are discussed in detail.     

Exchange Rate Volatility, Nominal Rigidities, and Persistent Deviations from PPP

It is shown how nominal exchange rate volatility can cause persistent deviations in the real exchange rate. The key to nominal rigidities is a capital market imperfection implying that agents cannot hedge perfectly against consumption risks. As a consequence, nominal changes have real effects by both affecting the ex post real purchasing power of savings and by affecting the ex ante incentives in savings and labor supply. The consequences of exogenous changes in the nominal exchange rate are considered in an OLG version of a two sector small open economy with competitive product and labor markets.J. Japan. Int. Econ.,December 1997,11(4), pp. 584–609. Department of Economics, University of Aarhus, 8000 Aarhus, Denmark.     

Financing budget deficits in the Netherlands

Summary In The Netherlands public debt management is in the hands of the budgetary policy-maker, whose recourse to the capital market can exceed or fall short of the total borrowing requirement in order to absorb or create liquidity. The conduct of that policy since the early 1960's is analyzed in this paper, emphasizing the importance of medium-term control over the public finances as a prerequisite for the ability of debt management to make a flexible contribution to monetary policy. During the 1960's this condition was satisfied and debt management followed a stable countercyclical pattern which, however, was abandoned after the early 1970's as the public finances swung into substantial disequilibrium.The author thanks J. Boughton, L. Bovenberg, D. Hendry, P. Masson, J. Muellbauer, and the referees for comments on earlier versions. However, the views expressed are his alone and do not necessarily represent those of the International Monetary Fund.     

Exchange rate volatility and its impact on the transaction costs of covered interest rate parity

This paper provides empirical evidence on the linkage between foreign exchange market volatility and daily 90-day covered interest rate parity (CIP) conditions of the three major exchange rates against the US dollar (US$). Markov regime shifting models were utilized to generate time series of volatility regime probabilities and these were used to explain the first and second moments of the daily deviations from and the transaction cost bands around the covered parity conditions. We find a significant positive relationship between the deviations and the regime probabilities, indicating an increasing probability of higher volatility state being associated with rising deviations (both first and second moments) from the parity condition. Similar positive relationship is found for the transaction bands. Rising (falling) probabilities of high (low) volatility regimes increased the first and second moments of the bands. Furthermore, we find a higher volatility state combined with a US$ depreciation is associated with significantly higher volatility in the daily deviations than an appreciation. Also, US$ depreciation is associated with widening transaction bands. This suggests that the level of market uncertainty was higher when the US$ was depreciating.     

Average Monotonic Cooperative Games

A subclass of monotonic transferable utility (T.U.) games is studied: average monotonic games. These games are totally balanced. We prove that the core coincides with both the bargaining set à la Davis and Maschler and the bargaining set à la Mas-Colell. To obtain this result a technique based on reduced games is used. Journal of Economic Literature Classification Number: C71     

Finding Pareto Optimal Insurance Contracts

This paper deals with on-line computation—or step-wise learning—of Pareto optimal insurance contracts. Our approach tolerates that the loss distribution might be unknown, intractable, or not well specified. Thus we accommodate fairly inexperienced parties. Losses are here simulated or observed, one at a time, and they cause iterated revisions of the premium. The mechanical and global nature of probability calculus thereby yields to more tentative, myopic procedures, possibly closer to how humans operate or reason in face of risk. Sequential revisions may also reduce the expense of insurers' time and money in seeking sufficient statistics. Emphasized below is the remarkable simplicity and stability of the resulting adaptive procedures. Special attention goes to catastrophic risks, and to subsidized or competitive insurance.