Attitudes towards foreign policy have typically been explained by ideological and demographic factors. We approach this study from a different perspective and ex amine the extent to which foreign policy preferences correspond to genetic variation. Using data from the Minnesota Twin Family Study, we show that a moderate share of individual differences in the degree to which one's foreign policy preferences are hawkish or dovish can be attributed to genetic variation. We also show, based on a bivariate twin model, that foreign policy preferences share a common genetic source of variation with political ideology. This result presents the possibility that ideology may be the causal pathway through which genes affect foreign policy preferences.

The generalized Poisson distribution with parameters θ and λ was introduced by Consul and Jain (1973) and has recently found several instances of application in the actuarial literature. The most frequently used version of the distribution assumes that θ > 0 and 0 ≤ λ < 1, in which case the mean and variance are θ/(1 − λ) and θ/(1 − λ)3, respectively. These simple moment expressions, along with nearly all of the other theoretical results available for this distribution, fail when λ < 0 or λ > 1 (e.g., Johnson, Kotz, and Kemp, 1992, page 397). In these cases, even the definition of the probability mass function usually given in the literature is not properly normalized so that its values do not sum to unity. For this reason, it is common to truncate the support of the distribution and explicitly normalize the probability mass function. In this paper we discuss the estimation of the parameters of this truncated generalized Poisson distribution using a Bayesian method.

Shock models leading to various univariate and bivariate increasing failure rate (IFR) and decreasing mean residual life (DMRL) distributions are discussed. For proving the IFR properties, shocks are not necessarily assumed to be governed by a Poisson process.

Suppose (X 1, Y 1), (X 2, Y 2), …, (Xn , Yn ) are independent random vectors such that a ≦ Xi ≦ b and a ≦ Yi ≦ b, i = 1, 2, …, n. An upper bound which exponentially converges to zero is derived for the probability Pr{Sx – nμ x ≧ nt 1;SY – nμY ≧ nt 2} where Sx = Σ Xi , SY = Σ Yi ,EYi = μY, EXi = μx and t 1 > 0, t2 > 0. The bound is a function of the difference b — a, the correlation between Xi and Yi, μx and μY and t 1 and t 2 .

A simple model for a bivariate birth-death process is proposed. This model approximates to the host-vector epidemic situation. An investigation of the transient process is made and the mean behaviour over time is explicitly found. The probability of extinction and the behaviour of the process conditional upon extinction are examined and the probability distribution of the cumulative population size to extinction is found. Appropriate circumstances are suggested under which the model might possibly be applied to malaria. The host-vector model is classified within a general class of models which represent large population approximations to epidemics involving two types of infectives.