The paper considers tests for the presence of a random walk component in a stationary or trend stationary time series and extends them to series which contain structural breaks. The locally best invariant (LBI) test is derived and the asymptotic distribution obtained. Then a modified test...

Lorenz curves and associated tools for ranking income distributions are commonly estimated on the assumption that full, unbiased samples are available. However, it is common to find income and wealth distributions that are routinely censored or trimmed. We derive the sampling distribution for a...

This article examines the links that have recently been studied between poverty, high fertility and undernourishment, on the one hand, and degradation of the local environmental-resource base and civic disconnection, on the other, in poor countries. An account is offered of a number of pathways...

We identify and investigate the basic ‘hold-up problem’ which arises whenever each party to a contract has to pay some ex-ante cost for the contract to become feasible. We then proceed to show that, under plausible circumstances, a ‘contractual solution’ to this hold-up problem is not...

Natural capital should be preserved because it exhibits features that distinguish it from all other kinds of capital. The notorious prevalence of risk, uncertainty and ignorance makes it difficult, however, to state which parts of it should be preserved. Some forms of natural capital are more...

The paper characterises the choice rules that can be implemented when agents are unable to commit themselves not to renegotiate the mechanism.

This paper analyses a dynamic game of investment in R&D or advertising, where current investments change future market conditions. It investigates whether underinvestment can be supported in equilibrium by the threat of escalation in investment outlays. When there are no spillovers, or there is...

There has recently been great interest in time series with long memory, namely series whose dependence decays slowly in the sense that autocovariances are not summable and the spectral density is unbounded. This concept has been extended to SCLM (Seasonal/Cyclical Long Memory) where the...

It is pointed out that two contradictory definitions of fractional Brownian motion are well established, one prevailing in the probabilistic literature, the other in the econometric literature. Each is associated with a different definition of nonstationary fractional time series, arising in...