1 Introduction This paper is concerned with the use of stock indices futures to hedge the return on portfolios. This topic has received considerable attention in the literature, which will be briefly summarised in section 2 of the paper. First of all it is desirable to consider the nature of hedging. The main aim of hedging is assumed to be the minimisation of the variance of the return on the ...

We discuss the various explanations that have been offered to account for subjects’ behaviour in Wason’s famous selection task, and find them wanting. We argue that what is lacking is a good understanding of a subject’s semantics for the key expressions involved, and an understanding of how this semantics is affected by the demands the task puts upon the subject’s cognitive system.

It is known that AND-EXOR two-level networks obtained by AND-EXOR expressions with positive literals are easily testable. They are based on the single-rail-input logic, and require (n + 4) tests to detect their single stuck-at faults, where n is the number of the input variables. We present three-level networks obtained from single-rail-input OR-ANDEXOR expressions and propose a more easily tes...

This paper uncovers an increasing proportion of quoted UK companies omitting cash dividends. Using a large panel of quoted UK companies, we estimate models for the incidence of dividend omissions and cuts as functions of financial characteristics including cash flow, leverage, investment opportunities, investment and company size. These variables account for most of the increase in omission sin...

Consider the random walk among N places with N(N - 1)/2 transports. We attach an exponential random variable Xij to each transport between places Pi and Pj and take these random variables mutually independent. If transports are possible or impossible independently with probability p and 1-p, respectively, then we give a lower bound for the distribution function of the smallest path at point log...