A research note on Keyfitz's "The demographics of unfunded pensions.".
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"In this paper, we examine the optimal pay-as-you-go social security scheme which reallocates resources across generations in a changing environment, that is, with fluctuations in population growth rates and in productivity levels. We use an overlapping generations model along with a social welfare function consisting of the sum of generational utilities either unweighted or weighted by population size and a discount factor. We show how intergenerational resource sharing can be used to improve social welfare even though the extent of intergenerational redistribution is hampered by payroll tax deadweight losses...." The authors also consider the effects of an economy's openness on resource sharing. The geographical focus is on developed countries.
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"This paper analyzes the effects of lump-sum tax policy in an overlapping generations model in which consumers have uncertain longevity. It extends previous analyses by considering the case in which private insurance arrangements are actuarially unfair. In addition, it considers the polar case of actuarially fair insurance and the polar case of no insurance. A general condition for debt neutrality is derived. This condition depends explicitly on the degree of actuarial unfairness in insurance and on the extent to which parents care about the utility of their children."
A 1986 "model of public pensions is generalized to allow for endogenous fertility. We show that gifts to the old, which can be viewed as social security contributions, are always positive in the steady state. An optimal stationary allocation is sustainable if savings are zero and fertility is exogenous. However, the optimal allocation is in general not sustainable. In particular, if a government enforces a social security plan setting the pension level at the optimal gifts and individuals optimize under the pension constraint, the resulting sustainable outcome is in general different from either the optimal or Nash outcome." The geographical focus is on developed countries.
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"Children's altruism toward parents is allowed in a two-overlapping-generations model with endogenous fertility. Parents raise children because, when retired, they expect gifts from their children who are essentially a capital good. Individuals' behavior between generations is examined by analyzing a Nash equilibrium, which is then compared with a social planner's optimal allocation. The pay-as-you-go public pension program is viewed as the optimal gifts from the optimal allocation when the latter is implemented. The effect on fertility of the introduction of a capital market is also analyzed. The validity of the old-age security hypothesis is shown to depend on the parameters of utility and cost functions."
Hybrids between a strain of Bacillus subtilis isolated in our laboratory and having the ability to degrade xylan and other complex polysaccharides and Corynebacterium acetoacidophilum, a lysine producer, were prepared by protoplast fusion. Based on distinctive parental biochemical characteristics the fusants were grouped into 9 categories, viz. BC1 through BC9. Three of the hybrids, BC5, BC7a and BC7b, were tested for their ability to produce xylanase and lysine. Both BC7a and BC7b produced xylanase but BC5 did not, however all of them produced lysine albeit to different degrees. These results demonstrate that intergeneric gene transfer takes place through protoplast fusion between these 2 important genera of bacteria and some of the fusants inherit the useful traits of both the parents.
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This study has investigated DNA transformation in the Amphotericin-producing organism Streptomyces nodosus. Amphotericin B is an antifungal drug with severe side effects in humans and the availability of structural variants would aid investigations into the mode of action and cytotoxity of the drug. Analogs of related polyketide drugs have been rapidly made by genetic engineering of biosynthetic genes; however, this requires the introduction of foreign DNA into the host. Protocols for protoplast formation and regeneration were established; however, preparations were recalcitrant to DNA uptake. Electroporation-mediated methodologies also were not successful. Intergeneric conjugal transfer of DNA from E. coli demonstrated transformation efficiencies of 5 x 10(-5) exconjugants generated per recipient. Use of DNA methylation-impaired E. coli donor strains resulted in 100-fold higher transformation efficiencies, indicating that DNA methylation recognition systems are operable in the organism. This methodology will enable genetic and biochemical analysis of the gene cluster responsible for making Amphotericin B.
"The family system practiced in the rural Franche-Comte [France] until the nineteenth century was based on egalitarian inheritance among sons and on the exclusion of daughters; as such, it was associated with distinct Malthusian nuptiality. This system cannot be understood without an examination of the formation and dynamics of a type of family that included frequent stages of undivided patrimony and coresidence in a context giving little encouragement to neolocal marriage and to the independence of sons. A comparative perspective suggests certain similarities with the stem family system, despite differences in inheritance norms.... Acceptance of the common idea of a contrast between impartible and partible inheritance should be highly qualified, insofar as partibility can hide various patterns of social reproduction. Different kinds of joint family household systems must be distinguished carefully, for they have neither the same significance nor imply the same demographic patterns."
"To study the influence of the city on the demographic behavior of rural people, family genealogies extending back to the beginning of the eighteenth century were reconstructed for a community near the city of Geneva [Switzerland].... The article examines kinship relations and kin network in this community at different ages.... The findings reveal a small kinship group surrounding the stable family unit, with generations overlapping sufficiently to assure the transmission of landed property as well as social reproduction without discontinuity and without the need to appeal to collateral kin for help."