The Family as an Incomplete Annuities Market

A new empirical study of the relation between money, nominal income, prices, and real output in postwar quarterly U.S. data rejects virtually all of the conclusions reached by Families provide individuals with risk sharing opportunities which may not otherwise be available. Within the family there is a degree of trust and a level of information which alleviates three key problems in the provision of insurance by markets open to the general public, namely, moral hazard, adverse selection, and deception. The informational advantages of pooling risk within families must be set against the inability of families to provide complete insurance because of the small size of the risk pooling group. This paper demonstrates how families can provide insurance against uncertain dates of death. Death risk sharing family arrangements effectively constitute an incomplete annuities market. Our analysis indicates that these arrangements even in small families can substitute by more than70% for complete annuities. Given the adverse selection problem and transactions costs in public annuity markets, risk pooling in families may well be preferred to purchasing market annuities. In the absence of organized public markets in annuities, these risk sharing arrangements provide powerful economic incentives for marriage and family formation. The paper suggests that inter-family transfers need have nothing to do with altruistic feelings; rather, they may simply reflect risk sharing behavior of completely selfish family members.

Origin of matter out of pure curvature

We propose a mechanism for origin of matter in the universe in the framework of Einstein-Gauss-Bonnet gravity in higher dimensions. The recently discovered new static black hole solution by the authors \cite{md2006} with the Kaluza-Klein split up of spacetime as a product of the usual {\ma M}^4 with a space of negative constant curvature is indeed a pure gravitational creation of a black hole which is also endowed with a Maxwell-like {\it gravitational charge} in four-dimensional vacuum spacetime. Further it could be envisioned as being formed from anti-de Sitter spacetime by collapse of radially inflowing charged null dust. It thus establishes the remarkable reciprocity between matter and gravity - as matter produces gravity (curvature), gravity too produces matter.Comment: 8 pages, 1 Fig, Received Honorable Mention in 2007 GRF Essay Competition, Summary of the talk given at Himalayan Relativity Dialogue at Mirik, April 18-20, 200

The Impact of Annuity Insurance on Savings and Inequality

This is the first paper to document the effect of health on the migration propensities of African Americans in the American past. Using both IPUMS and the Colored Troops Sample of the Civil War Union Army Data, I estimate the effects of literacy and health on the migration propensities of African Americans from 1870 to 1910. I find that literacy and health shocks were strong predictors of migration and the stock of health was not. There were differential selection propensities based on slave status—former slaves were less likely to migrate given a specific health shock than free blacks. Counterfactuals suggest that as much as 35% of the difference in the mobility patterns of former slaves and free blacks is explained by differences in their human capital, and more than 20% of that difference is due to health alone. Overall, the selection effect of literacy on migration is reduced by one-tenth to one-third once health is controlled for. The low levels of human capital accumulation and rates of mobility for African Americans after the Civil War are partly explained by the poor health status of slaves and their immediate descendants.

Thermal conductance measurements of pressed OFHC copper contacts at liquid helium temperatures

The thermal conductance of oxygen-free high conductivity (OFHC) copper sample pairs with surface finishes ranging from 0.1 to 1.6-micrometers rms roughness was investigated over the range of 1.6 to 6.0-K under applied contact forces up to 670 N. The thermal conductance increases with increasing contact force; however, no correlation can be drawn with respect to surface finish

Performance of all-metal demountable cryogenic seals at superfluid helium temperatures

Two all-metal demountable cryogenic seals with an outside diameter of 36.6 mm, inside diameter of 27.2 mm, and thickness of 0.51 mm were leak-tested at room temperature (300 K), liquid nitrogen temperature (21 cycles at 77 K), liquid helium temperature (9 cycles at 4.2 K), and susperfluid helium temperature (4 cycles at 1.6 K). Each seal was mounted and demounted for 13 cycles. Thickness measurements at 90 deg intervals along the circumference showed a maximum seal compression of 0.038 mm. Leak-rate measurements at all temperatures showed no detectable leak above the helium background level, typically 0.1 x 10(-9) std-cc/sec, during testing

Thermal conductance of pressed contacts at liquid helium temperatures

The thermal contact conductance of a 0.4 micrometer surface finish OFHC copper sample pair has been investigated from 1.6 to 3.8 K for a range of applied contact forces up to 670 N. Experimental data have been fitted to the relation Q = the integral alpha T to the nth power dt by assuming that the thermal contact conductance is a simple power function of the sample temperature. It has been found that the conductance is proportional to T squared and that conductance increases with an increase in applied contact force. These results confirm earlier work

Annuity Markets, Savings, and the Capital Stock

This article examines how the availability of annuities affects savings and inequality in economies in which neither private nor public pensions initially exist. The absence of widespread market or government annuity insurance is clearly descriptive of many less developed countries in the world today; it was also a characteristic of virtually all countries prior to World War II. The paper compares economies with perfect insurance with economies in which completely selfish parents and children pool longevity risk to their mutual advantage. The analysis of the latter economies takes into account the infinite sequence of risk sharing bargains of successive parents with their children. Such bargains affect current risk sharing between parents and child because they determine the welfare of current children when they become parents. Calculations based on the CBS utility function indicate that perfecting annuity insurance can significantly reduce national savings. Indeed, the insurance aspects of government pensions are potentially as important as underfunding government pensions in reducing national savings.

A helium-3 refrigerator employing capillary confinement of liquid cryogen

A condensation refrigerator suitable for operation in a zero gravity space environment was constructed. The condensed liquid refrigerant is confined by surface tension inside a porous metal matrix. Helium-4 and helium-3 gases were condensed and held in a copper matrix. Evaporative cooling of confined liquid helium-4 resulted in a temperature of 1.4K. Using a zeolite adsorption pump external to the cryostat, a temperature of 0.6 K was achieved through evaporative cooling of liquid helium-3. The amount of time required for complete evaporation of a controlled mass of liquid helium-4 contained in the copper matrix was measured as a function of the applied background power. For heating powers below 18 mW the measured times are consistent with the normal boiling of the confined volume of liquid refrigerant. At background powers above 18 mW the rapid rise in the temperature of the copper matrix the signature of the absence of confined liquid occurs in a time a factor of two shorter than that expected on the basis of an extrapolation of the low power data

Thermal conductance of pressed aluminum and stainless steel contacts at liquid helium temperatures

The thermal conductance of aluminum and stainless steel 304 sample pairs with surface finishes ranging from 0.1 to 1.6 microns rms roughness was investigated over a temperature range from 1.6 to 6.0 k. The thermal conductance follows a simple power law function of temperature, with the exponent ranging from 0.5 to 2.25, increases asymptotically with increasing applied force, and exhibits an anomaly for surface finishes in the 0.4 micron region