Non-Archimedean Preferences Over Countable Lotteries

We prove a representation theorem for preference relations over countably infinite lotteries that satisfy a generalized form of the Independence axiom, without assuming Continuity. The representing space consists of lexicographically ordered transfinite sequences of bounded real numbers. This result is generalized to preference orders on abstract superconvex spaces

How Much is at Stake for the Pragmatic Encroacher

“Pragmatic encroachers” about knowledge generally advocate two ideas: (1) you can rationally act on what you know; (2) knowledge is harder to achieve when more is at stake. Charity Anderson and John Hawthorne have recently argued that these two ideas may not fit together so well. I extend their argument by working out what “high stakes” would have to mean for the two ideas to line up, using decision theory

On the Probability of Plenitude

I examine what the mathematical theory of random structures can teach us about the probability of Plenitude, a thesis closely related to David Lewis's modal realism. Given some natural assumptions, Plenitude is reasonably probable a priori, but in principle it can be (and plausibly it has been) empirically disconfirmed—not by any general qualitative evidence, but rather by our de re evidence

Sleeping Beauty's Evidence

What degrees of belief does Sleeping Beauty's evidence support? That depends

Microstructure noise, realized volatility, and optimal sampling

Recorded prices are known to diverge from their "efficient" values due to the presence of market microstructure contaminations. The microstructure noise creates a dichotomy in the model-free estimation of integrated volatility. While it is theoretically necessary to sum squared returns that are computed over very small intervals to better identify the underlying quadratic variation over a period, the summing of numerous contaminated return data entails substantial accumulation of noise. Using asymptotic arguments as in the extant theoretical literature on the subject, we argue that the realized volatility estimator diverges to infinity almost surely when noise plays a role. While realized volatility cannot be a consistent estimate of the quadratic variation of the log price process, we show that a standardized version of the realized volatility estimator can be employed to uncover the second moment of the (unobserved) noise process. More generally, we show that straightforward sample moments of the noisy return data provide consistent estimates of the moments of the noise process. Finally, we quantify the finite sample bias/variance trade-off that is induced by the accumulation of noisy observations and provide clear and easily implementable directions for optimally sampling contaminated high frequency return data for the purpose of volatility estimationMicrostructure noise, realized volatility

Forecasting Transaction Rates: The Autoregressive Conditional Duration Model

This paper will propose a new statistical model for the analysis of data that does not arrive in equal time intervals such as financial transactions data, telephone calls, or sales data on commodities that are tracked electronically. In contrast to fixed interval analysis, the model treats the time between observation arrivals as a stochastic time varying process and therefore is in the spirit of the models of time deformation initially proposed by Tauchen and Pitts (1983), Clark (1973) and more recently discussed by Stock (1988), Lamoureux and Lastrapes (1992), Muller et al. (1990) and Ghysels and Jasiak (1994) but does not require auxiliary data or assumptions on the causes of time flow. Strong evidence is provided for duration clustering beyond a deterministic component for the financial transactions data analyzed. We will show that a very simple version of the model can successfully account for the significant autocorrelations in the observed durations between trades of IBM stock on the consolidated market. A simple transformation of the duration data allows us to include volume in the model.

Exploring Students’ Experiences with Expressive Writing

Expressive writing is defined as a therapeutic writing technique that individuals can use to engage in the process of expressing one’s emotions through writing about a past traumatic experience (Bryan & Lu, 2016; Pennebaker & Beall, 1986). Although there has been considerable empirical evidence showing that expressive writing can have a strong, positive effect on physical health as well as some evidence that there are benefits for mental health (Baikie & Wilhelm, 2005; Baikie, Geerligs, & Wilhelm, 2012; Hirai, Skidmore, Clum, & Dora, 2012; Pennebaker & Beall, 1986), there is a lack of knowledge about the experiences that individuals have when participating in the expressive writing process. Furthermore, the expressive writing literature lacks exploration of the process in a community college setting. The purpose of this study was to examine how students make meaning of their experience with the expressive writing process. Using an exploratory, qualitative approach, seven participants from a community college completed two expressive writing exercises about an obstacle they had faced while attending college. The seven participants were interviewed after the process, and each interview was transcribed and analyzed. Six themes emerged from the analysis of the interview data: “Affirmation of Accomplishments,” “Relief and Relaxation,” “Awareness of Future,” “Writing Concerns,” “Organization and Chronological Order of the Writing Process,” and “Reflection.” Each theme provided multiple perspectives of the experience to give a clearer picture of the mechanisms involved in the process of expressive writing, an in-depth view of the expressive writing process, and a stronger understanding of the meaning behind the experience of expressive writing. The implications for practice include how expressive writing could help community college students learn from stressful events in their academic career, process their thoughts and emotions, reduce anxiety, and gain a new perspective on their goals through the process of reflection. Finally, recommendations for future research are addressed, such as exploring emotion words, comparing different social, race, and gender characteristics in different community college populations, and exploring how grammar and punctuation skills can affect the expressive writing process

Major eastern wheatbelt soils to characterise soil moisture availability

In the Eastern Wheatbelt of Western Australia, there are seven major soil groups (acid sands, good soilplain soils, gravelly sands, duplex soils, medium-heavy soils, heavy non-friable soils and heavy friable soils. This report considers the ability of various soils to store or retain water in an attempt to partially determine the yield potential of crops

A History of the Developments of Fraternization Policies

Criticisms of the Air Force\u27s fraternization policy predominantly conclude that the prohibition of fraternization is based upon a caste system, which evolved from the class divisions of the Middle Ages and is designed to maintain those social divisions. The Air Force maintains that fraternization policies are necessary because fraternization adversely affects morale and discipline. This study uses qualitative research methods, ethnography and grounded theory, to consider the impacts of military customs, military structure, and societal structure to analyze the evolution of fraternization policies through Western military history as they relate to the development of the current Air Force policy. This study traces the development of fraternization policies through the Roman military, the Middle Ages, the national European armies preceding the American Revolution, and American history through the evolution of the Air Force. The study concludes that parallels between military ranks and social classes simplified enforcement of fraternization policies; however, the historical purpose of prohibiting fraternization was based on the need to maintain good order and discipline, not to maintain a social caste system. This purpose has been consistent throughout Western military history. The current Air Force policy is consistent with the historical purpose: to maintain good order and discipline