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We extend the Annually Recalculated Virtual Annuity (ARVA) spending rule for retirement savings decumulation (Waring and Siegel (2015) Financial Analysts Journal, 71(1), 91–107) to include a cap and a floor on withdrawals. With a minimum withdrawal constraint, the ARVA strategy runs the risk of depleting the investment portfolio. We determine the dynamic asset allocation strategy which maximizes a weighted combination of expected total withdrawals (EW) and expected shortfall (ES), defined as the average of the worst 5% of the outcomes of real terminal wealth. We compare the performance of our dynamic strategy to simpler alternatives which maintain constant asset allocation weights over time accompanied by either our same modified ARVA spending rule or withdrawals that are constant over time in real terms. Tests are carried out using both a parametric model of historical asset returns as well as bootstrap resampling of historical data. Consistent with previous literature that has used different measures of reward and risk than EW and ES, we find that allowing some variability in withdrawals leads to large improvements in efficiency. However, unlike the prior literature, we also demonstrate that further significant enhancements are possible through incorporating a dynamic asset allocation strategy rather than simply keeping asset allocation weights constant throughout retirement.
The rising popularity of hobbyist metal detecting has provided early medieval scholars with various important new datasets, not least the concentrations of metalwork commonly known as ‘productive sites’. Awareness of these foci derives almost exclusively from archaeological evidence, yet they continue to be interpreted through a documentary lens, and are frequently labelled ‘monasteries’. Using the recently discovered site of Little Carlton, Lincolnshire, as a case study, it is argued that comprehension of metal-rich sites is significantly furthered by turning to archaeologically-orientated research agendas and terminologies. As a consequence, seventh- to ninth-century Little Carlton can be understood as one element of a high-status ‘meshwork’ within early medieval East Lindsey, in which elite power was articulated in the landscape through a number of contemporary centres. On site, archaeology indicates the presence of occupation, burial and craft working, but shows that highly symbolic indigenous practices were taking place too, including intentional deposition into a naturally-occurring pond. Evidence for activity either side of the seventh to ninth centuries also stresses the importance of long-term trajectories in shaping the character of places previously celebrated for their finds-rich phases alone.
The COVID-19 pandemic has impacted community mental health, but the effect on psychiatric admissions is unknown. We investigated factors contributing to acute psychiatric admissions, and whether this changed during the first UK lockdown.
A retrospective case-note review study with an exploratory mixed-methods design was used to examine factors in psychiatric admissions following the first UK 2020 lockdown compared to the same time periods in 2019 and 2018.
Themes of psychopathology, risk, social stressors, community treatment issues, and physical health concerns were generated. The mean number of codes per case was 6⋅19 (s.d. = 2⋅43), with a mean number of categories per case of 3⋅73, (s.d. = 0⋅98). Changes in routines and isolation were common factors in the study year; accommodation and substance abuse were more prominent in the control year. Relationship stressors featured strongly in both groups. There were significantly more women (χ2(1, N = 98) = 20⋅80, p < 0⋅00001) and older adults (χ2(1, N = 98) = 8⋅61, p = 0⋅0033) in the study group than the control. Single people, compared to those in a relationship (χ2(1, N = 45) = 4.46, p = 0⋅035), and people with affective disorders compared to psychotic disorders ((χ2(1, N = 28) = 5.19, p = 0⋅023), were more likely to have a COVID-19 related admission factor.
The COVID-19 pandemic amplified pre-existing psychosocial vulnerabilities with a disproportionate psychiatric admissions impact on the mental health of women, the elderly and those with affective disorders.
There is presently a debate between Subjectivists and Objectivists about moral wrongness. Subjectivism is the view that the moral status of our actions, whether they are morally wrong or not, is grounded in our subjective circumstances – either our beliefs about, or our evidence concerning, the world around us. Objectivism, on the other hand, is the view that the moral status of our actions is grounded in our objective circumstances – all those facts other than those which comprise our subjective circumstances. A third view, Ecumenism, has it that the moral status of our actions is grounded both in our subjective and our objective circumstances. After outlining and evaluating the various arguments both against Subjectivism and against Objectivism, this Element offers a tentative defense of Objectivism about moral wrongness.
Tyler Burge first introduced his distinction between epistemic entitlement and epistemic justification in ‘Content Preservation’ in 1993. He has since deployed the distinction in over twenty papers, changing his formulation around 2011. His distinction and its basis, however, is not well understood in the literature. This chapter distinguishes two uses of ‘entitlement’ in Burge and then focuses on the contrast between justification and entitlement, two forms of warrant, where warrants consists in the exercise of a reliable belief-forming competence. Since he draws the distinction in terms of reasons, this chapter brings his account of reasons altogether in one place. The chapter introduces a decision-procedure for classifying warrants as justifications or entitlements. The distinction is not the same as the inferential vs. non-inferential distinction. Inference is distinguished from processing, thinking, reasoning, and critically reasoning. Burge’s new formulation of the distinction was driven by the recognition of non-accessible modular reasons. Three kinds of access are distinguished.
How should we undertand the role of norms – especially epistemic norms – governing assertive speech acts? Mitchell Green (2009) has argued that these norms play the role of handicaps in the technical sense from the animal signals literature. As handicaps, they then play a large role in explaining the reliability – and so the stability (the continued prevalence) – of assertive speech acts. But though norms of assertion conceived of as social norms do indeed play this stabilizing role, these norms are best understood as deterrents and not as handicaps. This paper explains the stability problem for the maintenance of animal signals, and so human communication; the mechanics of the handicap principle; the role of deterrents and punishments as an alternative mechanism; and the role of social norms governing assertion for the case of human communication.
The ‘jumping to conclusions’ (JTC) bias is associated with both psychosis and general cognition but their relationship is unclear. In this study, we set out to clarify the relationship between the JTC bias, IQ, psychosis and polygenic liability to schizophrenia and IQ.
A total of 817 first episode psychosis patients and 1294 population-based controls completed assessments of general intelligence (IQ), and JTC, and provided blood or saliva samples from which we extracted DNA and computed polygenic risk scores for IQ and schizophrenia.
The estimated proportion of the total effect of case/control differences on JTC mediated by IQ was 79%. Schizophrenia polygenic risk score was non-significantly associated with a higher number of beads drawn (B = 0.47, 95% CI −0.21 to 1.16, p = 0.17); whereas IQ PRS (B = 0.51, 95% CI 0.25–0.76, p < 0.001) significantly predicted the number of beads drawn, and was thus associated with reduced JTC bias. The JTC was more strongly associated with the higher level of psychotic-like experiences (PLEs) in controls, including after controlling for IQ (B = −1.7, 95% CI −2.8 to −0.5, p = 0.006), but did not relate to delusions in patients.
Our findings suggest that the JTC reasoning bias in psychosis might not be a specific cognitive deficit but rather a manifestation or consequence, of general cognitive impairment. Whereas, in the general population, the JTC bias is related to PLEs, independent of IQ. The work has the potential to inform interventions targeting cognitive biases in early psychosis.
We determine the optimal asset allocation to bonds and stocks using an annually recalculated virtual annuity (ARVA) spending rule for DC pension plan decumulation. Our objective function minimizes downside withdrawal variability for a given fixed value of total expected withdrawals. The optimal asset allocation is found using optimal stochastic control methods. We formulate the strategy as a solution to a Hamilton–Jacobi–Bellman (HJB) Partial Integro Differential Equation (PIDE). We impose realistic constraints on the controls (no-shorting, no-leverage, discrete rebalancing) and solve the HJB PIDEs numerically. Compared to a fixed-weight strategy which has the same expected total withdrawals, the optimal strategy has a much smaller average allocation to stocks and tends to de-risk rapidly over time. This conclusion holds in the case of a parametric model based on historical data and also in a bootstrapped market based on the historical data.
We compared systematic and random survey techniques to estimate breeding population sizes of burrow-nesting petrel species on Marion Island. White-chinned (Procellaria aequinoctialis) and blue (Halobaena caerulea) petrel population sizes were estimated in systematic surveys (which attempt to count every colony) in 2009 and 2012, respectively. In 2015, we counted burrows of white-chinned, blue and great-winged (Pterodroma macroptera) petrels within 52 randomized strip transects (25 m wide, total 144 km). Burrow densities were extrapolated by Geographic Information System-derived habitat attributes (geology, vegetation, slope, elevation, aspect) to generate island-wide burrow estimates. Great-winged petrel burrows were found singly or in small groups at low densities (2 burrows ha−1); white-chinned petrel burrows were in loose clusters at moderate densities (3 burrows ha−1); and blue petrel burrows were in tight clusters at high densities (13 burrows ha−1). The random survey estimated 58% more white-chinned petrels but 42% fewer blue petrels than the systematic surveys. The results suggest that random transects are best suited for species that are widely distributed at low densities, but become increasingly poor for estimating population sizes of species with clustered distributions. Repeated fixed transects provide a robust way to monitor changes in colony density and area, but might fail to detect the formation/disappearance of new colonies.