Genetics and insurance in the United Kingdom 1995-2010: the rise and fall of scientific discrimination

Around the millennium there was extensive debate in the United Kingdom of the possible use of predictive genetic tests by insurance companies. Many insurance experts, geneticists and public policymakers appeared to believe that genetic test results would soon become widely used by the insurance industry. This expectation has not been borne out. This article outlines the history of exaggerated perceptions of the significance of genetic test results to insurance, with particular reference to the United Kingdom, suggesting reasons why they arose and also why they have declined. The article concludes with some speculation about how policy on genetics and insurance might develop in future

Convergence Analysis of the Approximate Newton Method for Markov Decision Processes

Recently two approximate Newton methods were proposed for the optimisation of Markov Decision Processes. While these methods were shown to have desirable properties, such as a guarantee that the preconditioner is negative-semidefinite when the policy is $\log$-concave with respect to the policy parameters, and were demonstrated to have strong empirical performance in challenging domains, such as the game of Tetris, no convergence analysis was provided. The purpose of this paper is to provide such an analysis. We start by providing a detailed analysis of the Hessian of a Markov Decision Process, which is formed of a negative-semidefinite component, a positive-semidefinite component and a remainder term. The first part of our analysis details how the negative-semidefinite and positive-semidefinite components relate to each other, and how these two terms contribute to the Hessian. The next part of our analysis shows that under certain conditions, relating to the richness of the policy class, the remainder term in the Hessian vanishes in the vicinity of a local optimum. Finally, we bound the behaviour of this remainder term in terms of the mixing time of the Markov chain induced by the policy parameters, where this part of the analysis is applicable over the entire parameter space. Given this analysis of the Hessian we then provide our local convergence analysis of the approximate Newton framework.Comment: This work has been removed because a more recent piece (A Gauss-Newton method for Markov Decision Processes, T. Furmston & G. Lever) of work has subsumed i

Paralinearization of the Dirichlet to Neumann operator, and regularity of three-dimensional water waves

This paper is concerned with a priori $C^\infty$ regularity for three-dimensional doubly periodic travelling gravity waves whose fundamental domain is a symmetric diamond. The existence of such waves was a long standing open problem solved recently by Iooss and Plotnikov. The main difficulty is that, unlike conventional free boundary problems, the reduced boundary system is not elliptic for three-dimensional pure gravity waves, which leads to small divisors problems. Our main result asserts that sufficiently smooth diamond waves which satisfy a diophantine condition are automatically $C^\infty$. In particular, we prove that the solutions defined by Iooss and Plotnikov are $C^\infty$. Two notable technical aspects are that (i) no smallness condition is required and (ii) we obtain an exact paralinearization formula for the Dirichlet to Neumann operator.Comment: Corrected versio

Determinacy in Discrete-Bidding Infinite-Duration Games

In two-player games on graphs, the players move a token through a graph to produce an infinite path, which determines the winner of the game. Such games are central in formal methods since they model the interaction between a non-terminating system and its environment. In bidding games the players bid for the right to move the token: in each round, the players simultaneously submit bids, and the higher bidder moves the token and pays the other player. Bidding games are known to have a clean and elegant mathematical structure that relies on the ability of the players to submit arbitrarily small bids. Many applications, however, require a fixed granularity for the bids, which can represent, for example, the monetary value expressed in cents. We study, for the first time, the combination of discrete-bidding and infinite-duration games. Our most important result proves that these games form a large determined subclass of concurrent games, where determinacy is the strong property that there always exists exactly one player who can guarantee winning the game. In particular, we show that, in contrast to non-discrete bidding games, the mechanism with which tied bids are resolved plays an important role in discrete-bidding games. We study several natural tie-breaking mechanisms and show that, while some do not admit determinacy, most natural mechanisms imply determinacy for every pair of initial budgets

Infinite-Duration Bidding Games

Two-player games on graphs are widely studied in formal methods as they model the interaction between a system and its environment. The game is played by moving a token throughout a graph to produce an infinite path. There are several common modes to determine how the players move the token through the graph; e.g., in turn-based games the players alternate turns in moving the token. We study the {\em bidding} mode of moving the token, which, to the best of our knowledge, has never been studied in infinite-duration games. The following bidding rule was previously defined and called Richman bidding. Both players have separate {\em budgets}, which sum up to $1$. In each turn, a bidding takes place: Both players submit bids simultaneously, where a bid is legal if it does not exceed the available budget, and the higher bidder pays his bid to the other player and moves the token. The central question studied in bidding games is a necessary and sufficient initial budget for winning the game: a {\em threshold} budget in a vertex is a value $t \in [0,1]$ such that if Player $1$'s budget exceeds $t$, he can win the game, and if Player $2$'s budget exceeds $1-t$, he can win the game. Threshold budgets were previously shown to exist in every vertex of a reachability game, which have an interesting connection with {\em random-turn} games -- a sub-class of simple stochastic games in which the player who moves is chosen randomly. We show the existence of threshold budgets for a qualitative class of infinite-duration games, namely parity games, and a quantitative class, namely mean-payoff games. The key component of the proof is a quantitative solution to strongly-connected mean-payoff bidding games in which we extend the connection with random-turn games to these games, and construct explicit optimal strategies for both players.Comment: A short version appeared in CONCUR 2017. The paper is accepted to JAC

Environmental Volunteering: Motivations, Modes and Outcomes

Volunteers play a key role in natural resource management: their commitment, time and labour constitute a major contribution towards managing environments in Australia and throughout the world. From the point of view of environmental managers much interest has focussed on defining tasks suitable to volunteers. However, we argue that an improved understanding of what motivates volunteers is required to sustain volunteer commitments to environmental management in the long term. This is particularly important given that multiple government programs rely heavily on volunteers in Australia, a phenomenon also noted in the UK, Canada, and the USA. Whilst there is considerable research on volunteering in other sectors (e.g. health), there has been relatively little attention paid to understanding environmental volunteering. Drawing on the literature from other sectors and environmental volunteering where available, we present a set of six broad motivations underpinning environmental volunteers and five different modes that environmental volunteering is manifested. We developed and refined the sets of motivations and modes through a pilot study involving interviews with volunteers and their coordinators from environmental groups in Sydney and the Bass Coast. The pilot study data emphasise the importance of promoting community education as a major focus of environmental volunteer groups and demonstrate concerns over the fine line between supporting and abusing volunteers given their role in delivering environmental outcomes.environment, volunteering, motivation, Natural Resource Management (NRM)