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

Private transfers and public policy in developing countries : a case study for Peru

Private interhousehold cash transfers are an important source of income in many developing countries. Although precise transfer patterns are only beginning to be researched, the authors review the preliminary evidence from other studies and conduct original analysis based on the recent Peru Living Standards Survey. The paper reveals that private transfers are being directed toward vulnerable groups in society. The poor, the elderly, the very young, the disabled, the unemployed, and female headed households all receive disproportionately more transfers than their share in the population. In Peru, the lowest income quintile's share in total income is increased by 14 percent as a result of private transfers. In contrast, public transfers ( mostly social security payments ) increase that quintile's income share by only 4 percent. The authors conclude by revealing that these findings are not consistent with a purely altruistic model of giving, which predicts a one to one substitution for public giving. They are consistent with theories of exchange and private insurance.Safety Nets and Transfers,Services&Transfers to Poor,Rural Poverty Reduction,Poverty Assessment,Banks&Banking Reform

In ISM Modeling, The Devil is in the Details: You Show Me Your OVI and I'll Show You Mine

The three sections of this paper illustrate the importance of rationalizing ISM theory and modeling with the observational information.Comment: To be published in "From Observations to Self-Consistent Modelling of the ISM in Galaxies", eds. M. Avillez & D. Breitschwerdt, Kluwer Astrophys. & Space Sci. Serie

A comparative analysis of methods used in preparation for occupational testing

Acceptable and recognized methods utilized to develop competency and prepare for occupational testing are strongly controlled by certifying agencies. Teachers, law enforcement officers, medical personnel and fire fighters, to name a few, operate under specific guidelines for training requirements to qualify for professional certification. Most certification examinations are competency based tests. What methods of preparation a certifying agency recognizes may severely restrict an individual\u27s option to develop competency.;This research thesis specifically investigates fire fighter certification and methods of preparation to develop competency. Over five-hundred Iowa fire fighter candidates from 1989 to 1991 were studied. Written examination scores were collected along with various demographic information.;Specific hypotheses studied involved methods of preparation; years of experience; volunteer vs. career fire fighters; and gender of the candidates

The Evolution of Altruistic Preferences: Mothers versus Fathers

What can evolutionary biology tell us about male-female differences in preferences concerning family matters? Might mothers be more solicitous toward offspring than fathers, for example? The economics literature has documented gender differences—children benefit more from money put in the hands of mothers rather than fathers, for example—and these differences are thought to be partly due to preferences. Yet for good reason family economics is mostly concerned with how prices and incomes affect behavior against a backdrop of exogenous preferences. Evolutionary biology complements this approach by treating preferences as the outcome of natural selection. We mine the well-developed biological literature to make a prima facie case for evolutionary roots of parental preferences. We consider the most rudimentary of traits—sex differences in gamete size and internal fertilization—and explain how they have been thought to generate malefemale differences in altruism toward children and other preferences related to family behavior. The evolutionary approach to the family illuminates connections between issues typically thought distinct in family economics, such as parental care and marriage markets

Timing synchronization in high mobility OFDM systems

Abstract — OFDM systems are sensitive to timing synchronization errors. Utilizing pilot-aided channel estimators in OFDM systems can further increase this sensitivity. This is shown in [2] where authors have analyzed the effect of such errors on a pilotaided channel estimator in a fixed wireless environment. They proposed an algorithm that exploits this sensitivity to improve timing synchronization without additional training overhead. The effect of these errors and design of suitable synchronization algorithms for high mobility applications, however, have not been studied before. In this paper we extend the analysis in [2] to high mobility environments. Timing synchronization becomes more challenging for mobile applications since powerdelay profile of the channel may change rapidly due to the sporadic birth and death of the channel paths. We find analytical expressions for channel estimation error in the presence of timing synchronization errors and mobility. We show that the sensitivity of the channel estimator can still be exploited to improve timing synchronization in high mobility environments. Then we extend the algorithm proposed in [2] to high mobility applications. Finally simulation results show the performance of the algorithm in high delay and Doppler spread environments. I

Supernova Remnant in a Stratified Medium: Explicit, Analytical Approximations for Adiabatic Expansion and Radiative Cooling

We propose simple, explicit, analytical approximations for the kinematics of an adiabatic blast wave propagating in an exponentially stratified ambient medium, and for the onset of radiative cooling, which ends the adiabatic era. Our method, based on the Kompaneets implicit solution and the Kahn approximation for the radiative cooling coefficient, gives straightforward estimates for the size, expansion velocity, and progression of cooling times over the surface, when applied to supernova remnants (SNRs). The remnant shape is remarkably close to spherical for moderate density gradients, but even a small gradient in ambient density causes the cooling time to vary substantially over the remnant's surface, so that for a considerable period there will be a cold dense expanding shell covering only a part of the remnant. Our approximation provides an effective tool for identifying the approximate parameters when planning 2-dimensional numerical models of SNRs, the example of W44 being given in a subsequent paper.Comment: ApJ accepted, 11 pages, 2 figures embedded, aas style with ecmatex.sty and lscape.sty package