Conservative Christian teachers: possible consequences for lesbian,gay and bisexual youth

This essay explores the effects evangelical and/or fundamentalist Christian educators could have on the experiences of lesbian, gay and bisexual (LGB) individuals in schools. Evangelical and/or fundamentalist Christian educators’ beliefs about LGB individuals may be at odds with the goals of equity, social justice and activism a true multicultural education provides. Teacher educators, in particular multicultural teacher educators, must understand the historical and social influences Christianity has on how LGB persons are perceived and how teachers who are fundamentalist and/or evangelical may consciously or unconsciously oppress and marginalize these students and other LGB members of the education community.     

Endogenous Completeness of Diffusion Driven Equilibrium Markets

We study the existence of dynamic equilibria with endogenously complete markets in continuous‐time, heterogenous agents economies driven by diffusion processes. Our main results show that under appropriate conditions on the transition density of the state variables, market completeness can be deduced from the primitives of the economy. In particular, we prove that a sufficient condition for market completeness is that the volatility of dividends be invertible and provide higher order conditions that apply when this condition fails as is the case in the presence of fixed income securities. In contrast to previous research, our formulation does not require that securities pay terminal dividends, and thus allows for both finite and infinite horizon economies.     

Modeling fetal-growth biometry with Response Modeling Methodology (RMM) and comparison to current models

Monitoring fetal growth via ultrasound requires modeling fetal biometry in terms of gestation age. In this study, we compare Response Modeling Methodology (RMM) to current models, in three stages. First, RMM is used to approximate 47 empirical mean models that have appeared in the literature resulting in models with negligible loss in accuracy (unlike two other commonly applied models). Next, RMM models are fitted to sample averages of the Singaporean population and compared to a formerly published model. A similar simulation-based analysis is performed in the last stage for raw data of the British population. Altogether over 70 comparisons had been performed resulting in RMM consistently delivering better performing models.     

Self-affine time series: measures of weak and strong persistence

In this paper, we examine self-affine time series and their persistence. Time series are defined to be self-affine if their power-spectral density scales as a power of their frequency. Persistence can be classified in terms of range, short or long range, and in terms of strength, weak or strong. Self-affine time series are scale-invariant, thus they always exhibit long-range persistence. Synthetic self-affine time series are generated using the Fourier power-spectral method. We generate fractional Gaussian noises (fGns), −1β1, where β is the power-spectral exponent. These are summed to give fractional Brownian motions (fBms), 1β3, where the series are self-affine fractals with fractal dimension 1D2; β=2 is a Brownian motion. With β>1, the time series are non-stationary and moments of the time series depend upon its length; with β<1 the time series are stationary. We define self-affine time series with β>1 to have strong persistence and with β<1 to have weak persistence. We use a variety of techniques to quantify the strength of persistence of synthetic self-affine time series with −3β5. These techniques are effective in the following ranges: (1) semivariograms, 1β3, (2) rescaled-range (R/S) analyses, −1β1, (3) Fourier spectral techniques, all values of β, and (4) wavelet variance analyses, all values of β. Wavelet variance analyses lack many of the inherent problems that are found in Fourier power-spectral analysis.     

Aging-related temporal constraints to stability and instability in postural control

In this study, we review the evidence that older adults tend to have both a shorter time to lose stability in the maintenance of standing posture and the functionally related but inverse problem of needing more time to reacquire stability in transitioning to a postural state. These age-related time limitations to processes of stability are hypothesized to enhance the probability of falling with aging and the problems that can occur in the transition between activities, such as sitting to standing and standing to walking. The potential role of fitness and health variables in mediating the temporal constraints on the acquisition and loss of postural stability in aging is discussed.     

Breadth versus Depth: The Timing of Specialization in Higher Education

This paper examines the trade‐off between early and late specialization in the context of higher education. I develop a model in which individuals accumulate field‐specific skills and receive noisy signals of match quality across different fields of study. I derive comparative static predictions between educational regimes with early and late specialization, and examine these predictions across British systems of higher education. Using survey data on 1980 university graduates, I find that individuals who switch to unrelated occupations have lower initial earnings, and that early specialization in England is associated with more costly switches. But higher wage growth among those who switch eliminates the wage difference after several years, and average earnings are not significantly different between England and Scotland.     

Information Percolation With Equilibrium Search Dynamics

We solve for the equilibrium dynamics of information sharing in a large population. Each agent is endowed with signals regarding the likely outcome of a random variable of common concern. Individuals choose the effort with which they search for others from whom they can gather additional information. When two agents meet, they share their information. The information gathered is further shared at subsequent meetings, and so on. Equilibria exist in which agents search maximally until they acquire sufficient information precision and then search minimally. A tax whose proceeds are used to subsidize the costs of search improves information sharing and can, in some cases, increase welfare. On the other hand, endowing agents with public signals reduces information sharing and can, in some cases, decrease welfare.