Playing Safe

We consider two-player games over graphs and give tight bounds on the memory size of strategies ensuring safety conditions. More specifically, we show that the minimal number of memory states of a strategy ensuring a safety condition is given by the size of the maximal antichain of left quotients with respect to language inclusion. This result holds for all safety conditions without any regularity assumptions, and for all (finite or infinite) graphs of finite degree. We give several applications of this general principle. In particular, we characterize the exact memory requirements for the opponent in generalized reachability games, and we prove the existence of positional strategies in games with counters

Playing Safe, Ten Years Later

We consider two-player games over graphs and give tight bounds on the memory size of strategies ensuring safety objectives. More specifically, we show that the minimal number of memory states of a strategy ensuring a safety objective is given by the size of the maximal antichain of left quotients with respect to language inclusion. This result holds for all safety objectives without any regularity assumptions. We give several applications of this general principle. In particular, we characterize the exact memory requirements for the opponent in generalized reachability games, and we prove the existence of positional strategies in games with counters

Playing safe: Assessing the risk of sexual abuse to elite child athletes

Young athletes frequently suffer from being seen as athletes first and children second. This has consequences for their legal, civil and human rights as children (Kelly et al., 1995) and for the way in which sport organisations choose to intervene on their behalf to protect them from physical, psychological and sexual abuses (Brackenridge, 1994). Sport careers peak at different ages depending on the sport: in some, children as young as 12 or 13 may reach the highest levels of competitive performance; in others, full maturity as an athlete may come late into adulthood or even middle age. Recognition of this variation has given rise to the concept of ‘sport age’ (Kirby, 1986) referring to sport-specific athlete development. This concept is of significance in helping to identify the developmental process in terms of athletic, rather than chronological, maturity. The risk of sexual abuse in sport, formerly ignored or denied, has now been documented in a number of studies, using both quantitative and qualitative methods (Kirby & Greaves, 1996; Brackenridge, 1997; Volkwein, 1996). Drawing on data from these studies and from the previous work on sport age and athletic maturation, this paper proposes a possible means of identifying and assessing relative risk of sexual abuse to elite young athletes in selected sports. The concept of a ‘stage of imminent achievement’ (SIA) is proposed as the period of peak vulnerability of young athletes to sexual abuse

Playing Safe, Ten Years Later

We consider two-player games over graphs and give tight bounds on the memory size of strategies ensuring safety objectives. More specifically, we show that the minimal number of memory states of a strategy ensuring a safety objective is given by the size of the maximal antichain of left quotients with respect to language inclusion. This result holds for all safety objectives without any regularity assumptions. We give several applications of this general principle. In particular, we characterize the exact memory requirements for the opponent in generalized reachability games, and we prove the existence of positional strategies in games with counters

Taxpayers' perceptions of the ideal tax adviser: Playing safe or saving dollars?

This paper empirically examines Australian taxpayers’ perceptions of their tax practitioners and ‘ideal’ tax practitioners, using a sample of 2040 randomly selected Australian taxpayers who completed the Community Hopes, Fears and Actions Survey (Braithwaite, 2000). This research identifies the basic dimensions that underlie taxpayer judgements of the attributes of their ideal tax practitioner. One kind of tax practitioner sought by certain taxpayers is the ‘creative accountant, aggressive tax planning type’. Here the taxpayer is also looking for a practitioner who is well networked and knows what the Australian Taxation Office (Tax Office) is checking at a particular time. This is by far the least popular preference among ordinary individual taxpayers, but clearly one of the greatest concern to tax authorities. A second type of practitioner sought by taxpayers is one who engages in ‘cautious minimisation of tax’. Unlike the creative accountants, practitioners of this type avoid conflict, while being sophisticated about identifying opportunity to minimise tax. The most popular type of practitioner with taxpayers is the ‘low risk, no fuss’ practitioner who is honest and risk averse. The data also show that taxpayers are likely to find tax practitioners who have the attributes they value most highly in a practitioner. Further work is needed to understand the matching process, in particular, how high risk practitioners and high risk taxpayers form their partnerships

Risk-Taking Tournaments: Theory and Experimental Evidence

We study risk-taking behavior in a simple two person tournament in a theoretical model as well as a laboratory experiment. First, a model is analyzed in which two agents simultaneously decide between a risky and a safe strategy and we allow for all possible degrees of correlation between the outcomes of the risky strategies. We show that risk-taking behavior crucially depends on this correlation as well as on the size of a potential lead of one of the contestants. We find that the experimental subjects acted mostly quite well in line with the derived theoretical predictions.tournaments, competition, risk-taking, experiment

Financial safety nets, bailouts and moral hazard

The paper argues that policymakers bail out banks with financial problems to avoid the costs of financial repression. After financial liberalization and when risk is verifiable, in some circumstances policymakers can commit to policies that discipline banks ex-ante and ex-post, by providing bailout to conservative banks and threatening the takeover of risky banks. When these policies are time consistent, regulatory policies to deal with moral hazard ex-ante, like for example prudential regulation, become redundant and policymakers refrain from implementing them.