402,483 research outputs found
Dynamics of a rational system of difference equations in the plane
We consider a rational system of first order difference equations in the
plane with four parameters such that all fractions have a common denominator.
We study, for the different values of the parameters, the global and local
properties of the system. In particular, we discuss the boundedness and the
asymptotic behavior of the solutions, the existence of periodic solutions and
the stability of equilibria
Modeling style rotation: switching and re-switching
The purpose of this paper is to investigate the dynamics and statistics of style rotation based on the Barberis-Shleifer model of style switching. Investors in stocks regard the forecasting of style-relative performance, especially style rotation, as highly desirable but difficult to achieve in practice. Whilst we do not claim to be able to do this in an empirical sense, we do provide a framework for addressing these issues. We develop some new results from the Barberis-Shleifer model which allows us to understand some of the time series properties of style relative price performance and determine the statistical properties of the time until a switch between styles. We apply our results to a set of empirical data to get estimates of some of the model parameters including the level of risk aversion of market participants
A Statistical Study of Wages, Prices and Employment in the. Irish Manufacturing Sector. General Research Series Paper No. 29, January 1966
This paper is concerned with the estimation of
certain economic relationships in the Irish economy.
It seems important that attempts be made to put
figures on relationships believed to exist (for instance
between the level of unemployment and annual
changes in earnings) rather than to speculate on these
relationships. This study tries to do this but it
is important to emphasise that this is an exercise in
statistics and that the statements made about these
relationships are essentially probability statements.
This means that the degree of certainty attached to
any set of figures in this study is far from being of
the same order as found in, say, calculations of future
eclipses. As it would be tedious to repeat this
qualification at almost every step in the paper the
author trusts it will be borne in mind. The figures
we get may be more usefully regarded as fairly reliable
orders of magnitude. This study was completed
in the summer vacation of 1964 and the
author realises only too dearly that it is an exploratory venture and as such cannot be expected to provide
complete answers on the topics covered.
But it is hoped that it provides a useful starting point
for further studies
Asymmetric adjustment in the City of London office market
Earlier estimates of the City of London office market are extended by considering a longer time series of data, covering two cycles, and by explicitly modeling of asymmetric space market responses to employment and supply shocks. A long run structural model linking real rental levels, office-based employment and the supply of office space is estimated and then rental adjustment processes are modeled using an error correction model framework. Rental adjustment is seen to be asymmetric, depending both on the direction of the supply and demand shocks and on the state of the space market at the time of the shock. Vacancy adjustment does not display asymmetries. There is also a supply adjustment equation. Two three-equation systems, one with symmetric rental adjustment and the other with asymmetric adjustment, are subjected to positive and negative shocks to employment. These illustrate differences in the two systems
Non-symmetric gravity waves on water of infinite depth
Two different numerical methods are used to demonstrate the existence of and calculate non-symmetric gravity waves on deep water. It is found that they appear via spontaneous symmetry-breaking bifurcations from symmetric waves. The structure of the bifurcation tree is the same as the one found by Zufiria (1987) for waves on water of finite depth using a weakly nonlinear Hamiltonian model. One of the methods is based on the quadratic relations between the Stokes coefficients discovered by Longuet-Higgins (1978a). The other method is a new one based on the Hamiltonian structure of the water-wave problem
On periodic solutions of 2-periodic Lyness difference equations
We study the existence of periodic solutions of the non--autonomous periodic
Lyness' recurrence u_{n+2}=(a_n+u_{n+1})/u_n, where {a_n} is a cycle with
positive values a,b and with positive initial conditions. It is known that for
a=b=1 all the sequences generated by this recurrence are 5-periodic. We prove
that for each pair (a,b) different from (1,1) there are infinitely many initial
conditions giving rise to periodic sequences, and that the family of
recurrences have almost all the even periods. If a is not equal to b, then any
odd period, except 1, appears.Comment: 27 pages; 1 figur
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