Understanding the Fanaroff-Riley radio galaxy classification

The simple, yet profoundly far-reaching classification scheme based on extended radio morphologies of radio galaxies, the Fanaroff-Riley classification has been a cornerstone in our understanding of radio galaxies. Over the decades since the recognition that there are two basic types of radio galaxy morphologies there have been several findings in different wavebands that have reported properties on different scales. Although it is realized that there may be intrinsic as well external causes an overarching view of how we may understand the two morphological types is missing. With the radio power-absolute magnitude relation (the Owen-Ledlow diagram) as backdrop we review and develop an understanding of the two radio galaxy types in the light of what is known about them. We have for the first time included the dust properties of the two FR classes together with the relative orientations of dust, host major axis and the radio axis to present a qualitative framework within which to understand the conditions under which they form. (Abridged).Comment: 15 pages, To appear in Astronomical Journa

Long Term Effects of Preschool Investment on school Performance and Labor Market Outcome

Using the NLSY data set, this paper formulates and then empirically estimates the production processes for social, motivational and cognitive skills during early childhood development and the long-term effects of these skills on learning and life-time earnings of an individual. Using these estimated relationships, the paper provides a calibrated intergenerational altruistic model of parental investment in children's preschool. This dynamic model is then used to estimate the effects of publicly provided preschool to the children of poor socioeconomic status (SES) on college mobility and intergenerational social mobility and to estimate the tax burden of such a social contract.Preschool Investment, Early Childhood Development, Intergenerational Social Mobility, College Mobility

Learning to Perfect Manipulation: Implications for Fertility, Savings, and Old-Age Social Security

In this paper we consider an overlapping gnerations model with endogenous fertility and two-sided altruism and show the limitations of applying commonly used open loop Nash equilibrium in characterizing equilibrium transfers from parents to children in the form of bequest, and transfers from children to parents as voluntary old-age support. Since in our model children are concerned with parents' old-age consumption, agents have incentives to save less for old age and to have more children so as to strategically induce their children to transfer more old-age support. We formulate such strategic behavior within a sequential multi-stage game and introduce a notion of learning equilibrium to characterize equilibrium manipulative behavior and then study the consequences of such strategic manipulations on private intergenerational transfers, fertility and savings decisions, and on Pareto optimality of equilibrium allocation. We show that the learning equilibrium notion of the paper simplifies computation of subgame perfect equilibrium, subgame perfect equilibrium is the long-run outcome of dynamic learning equilibrium paths (this aids in selecting, sometimes, a unique equilibrium among multiple subgame perfect equilibria), and an open-loop Nash equilibrium involves "incredible" threats from children. We provide an alternative explanation for the existence of publicly provided social security program and examine its role to correct distortions created by strategic manipulation.two-sided altruism, endogenous fertility, subgame perfect manipulation of children, social security

Developing teachers as researchers: A teacher preparation endeavor

Instructional process is aimed at accomplishing the desired learning outcomes. But some times teachers may fail to achieve the instructional objectives. In such instances teachers attempt to find out reasons that come in way of achieving the instructional goals. The reasons may pertain to student behavior, curriculum or teacher behavior. In order to improve their classroom practices for initiating desired learning outcomes, teachers often encountered with such question as why expected outcomes are not achieved, what are the impediments that caused non accomplishment of learning outcomes, how to improve instruction for better learning and so on. One of the major reasons for such situation may be due to gap between what teacher planned to do and what has been done in the actual classroom instruction. Teachers are expected to identify these gaps between their thought and action. Consequently, they should attempt to mitigate this gap to improve quality of instruction. In order to undertake this task, teachers need to play the role of a researcher. Teacher preparation programs should equip teachers with necessary skills of conducting classroom research. This helps teachers in improving their classroom practices. Teacher educators working in District Institutes of Education and Training (DIET) have to play an important role in equipping the teachers with the skills of conducting classroom research. Hence there is a need to improve the capabilities of DIET faculty to train primary teachers in conducting classroom research