On the Demand for Grandchildren: Tied Transfers and the Demonstration Effect

Most private giving between living generations takes the form of "tied" transfers, such as help with housing downpayments. We argue that parents provide help with downpayments in order to encourage the production of grandchildren, and that such a subsidization emanates from the "demonstration effect:" a child's propensity to furnish parents with attention and care can be conditioned by parental example. Parents who desire such transfers in the future have an incentive to make transfers to their own parents in order to instill appropriate preferences in their children. This generates a derived demand for grandchildren since potential grandparents will be treated better by their adult children if the latter have their own children to whom to demonstrate the appropriate behavior. Empirical work, based on waves 1 and 2 of the National Survey of Families and Households, indicates behavior consistent with subsidization of the production of grandchildren and the demonstration effect.Intergenerational transfers, The demonstration effect, Inculcating values in children, Subsidizing the production of grandchildren, Housing downpayments

Clause and sentence boundary markers in the Dakota language

From the introduction: Based on [the] recorded data [of a natural conversation], rather than on suggested or controlled informant responses to out-of-context situations, a procedure will be described by which the larger grammatical sequences (i.e., sentences and clauses) of Dakota may be delimited from the larger speech continua in which they are imbedded. 1.3 There are today two main views regarding the fundamental procedure to be followed in the linguistic analysis of a corpus of data, each with its group of adherents. One group considers that the analyst will obtain best results, save time, and produce a more accurate final description if he begins first with the identification and description of the smaller units, and then proceeds through word, to phrase, then to clause, and finally to discourse. The other offers identical rewards to those who apply this procedure in reverse, i.e., who begin by cutting the discourse first into paragraphs, then sentences, phrases, until the ultimate building blocks of grammar--the morphemes--are isolated. 1.4 The following sections of this paper will describe the method of elicitation used in obtaining the language data utilized herein, the phonology, and the procedure by which the sentence and clause boundaries within this Dakota discourse can be determined. The final section will present a phonemic transcription of the conversation text, with a literal translation; a free translation of the same text; and an inventory of particles and inflectional morphemes occurring throughout the data

Local variations in spatial synchrony of influenza epidemics

Background: Understanding the mechanism of influenza spread across multiple geographic scales is not complete. While the mechanism of dissemination across regions and states of the United States has been described, understanding the determinants of dissemination between counties has not been elucidated. The paucity of high resolution spatial-temporal influenza incidence data to evaluate disease structure is often not available. Methodology and Findings: We report on the underlying relationship between the spread of influenza and human movement between counties of one state. Significant synchrony in the timing of epidemics exists across the entire state and decay with distance (regional correlation = 62%). Synchrony as a function of population size display evidence of hierarchical spread with more synchronized epidemics occurring among the most populated counties. A gravity model describing movement between two populations is a stronger predictor of influenza spread than adult movement to and from workplaces suggesting that non-routine and leisure travel drive local epidemics. Conclusions: These findings highlight the complex nature of influenza spread across multiple geographic scales. © 2012 Stark et al

Stellar Iron Abundances at the Galactic Center

We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda =40,000) K-band spectra, taken with CSHELL at the NASA Infrared Telescope Facility.We determine the iron abundance by detailed abundance analysis,performed with the spectral synthesis program MOOG.The mean [Fe/H] of the GC stars is determined to be near solar,[Fe/H] = +0.12 $\pm$ 0.22. Our analysis is a differential analysis, as we have observed and applied the same analysis technique to eleven cool, luminous stars in the solar neighborhood with similar temperatures and luminosities as the GC stars. The mean [Fe/H] of the solar neighborhood comparison stars, [Fe/H] = +0.03 $\pm$ 0.16, is similar to that of the GC stars. The width of the GC [Fe/H] distribution is found to be narrower than the width of the [Fe/H] distribution of Baade's Window in the bulge but consistent with the width of the [Fe/H] distribution of giant and supergiant stars in the solar neighborhood.Comment: 41 pages, 9 figures, ApJ, in pres

Multiple light scattering in anisotropic random media

In the last decade Diffusing Wave Spectroscopy (DWS) has emerged as a powerful tool to study turbid media. In this article we develop the formalism to describe light diffusion in general anisotropic turbid media. We give explicit formulas to calculate the diffusion tensor and the dynamic absorption coefficient, measured in DWS experiments. We apply our theory to uniaxial systems, namely nematic liquid crystals, where light is scattered from thermal fluctuations of the local optical axis, called director. We perform a detailed analysis of the two essential diffusion constants, parallel and perpendicular to the director, in terms of Frank elastic constants, dielectric anisotropy, and applied magnetic field. We also point out the relevance of our results to different liquid crystalline systems, such as discotic nematics, smectic-A phases, and polymer liquid crystals. Finally, we show that the dynamic absorption coefficient is the angular average over the inverse viscosity, which governs the dynamics of director fluctuations.Comment: 23 pages, 12 ps figures, to be published in Phys. Rev.