8,745 research outputs found
Solar power R and D for Air Force space requirements
The requirements for improved solar power system technology for DOD satellites are reported. It is shown that the technology is required in several areas including solar cells, array blanket technology, energy storage and power system operation, and regulation and control. It is further shown that as the missions become more critical to defence, military aspects such as survivability, hardening, and eventually defence must be addressed
Future Air Force space power needs
The requirements for future power for AF satellite mission vehicles, fall into two categories. The first category is in the 1 to 50 kW range for missions of a continuous nature such as communication, navigation, surveillance, data relay and meteorology. The second category is in the multi-megawatt range for either continuous or burst power durations and are for other than solar power sources. Requirements for longer life and survivability in varying degrees are there for all systems. While the power levels do not appear difficult to achieve in view of the large array developments pursued by NASA Space Station technology, the other military requirements are very challenging and continue to be system drivers. The development of solar cells arrays should be in conjunction with other power supply technologies such as regulation and control components and energy storage subsystems
Air Force and DOD solar power requirements
It is noted that future power requirements are increasing for some expanded and new missions within the Air Force and Department of Defense. New requirements are needed in terms of lifetime, survivability, power level and performance. The photovoltaic arrays have a demonstrated record of reliable performance, life, affordable cost, and utility. It is argued that there is a need to push for the research and development resources needed to develop the technology base for these future power system needs
The Wealth of Cohorts: Retirement Saving and the Changing Assets of Older Americans
Personal retirement accounts are becoming an increasingly important form of retirement saving. Using data from the Survey of Income and Program Participation, the paper considers the effect of this change on the assets of recent retirees and persons who are approaching retirement. Much of the analysis is based on comparison of younger and older cohorts with different lengths of exposure to personal retirement saving programs. The findings suggest that personal retirement saving has already added substantially to the personal financial assets of older families. Projections imply that the personal financial assets of the cohort that will attain age 76 in 28 years will be almost twice as large as the personal financial assets of the cohort that attained age 76 in 1991. The results indicate also that to date there has been little replacement of employer-provided pension saving with personal retirement saving. Together with evidence that personal financial saving is unrelated to changes in home equity, the results suggest that personal retirement saving will lead to an important increase in the overall wealth of the elderly.
The Determinants of IRA Contributions and the Effect of Limit Changes
Tax-deferred savings are potentially an important component of savings for retirement and could represent a very substantial increase in tax-free savings for many employees. IRAs may also have a substantial effect on national savings. Total IRA contributionsin 1982 were over 29 billion dollars. Despite the program's size and potential significance, little is known about the determinants of IRA contributions.This paper presents: (1) analysis of the effect of individual attributes on whether a person contributes, (2) analysis of the effect of individual attributes on how much is contributed,and (3) simulations of the effect of potential changes in contribution limits on the amount that is contributed to IRA accounts. Results of a similar analysis based on Canadian data are compared with results for the United States. Persons with low incomes are unlikely to have IRA accounts. In addition, after controlling for income, age, and other variables, persons without private pension plans are no more likely than those with them to Contribute to an IRA. The analysis of Canadian data yields similar findings, and indeed specific parameter estimates for the two countries are very similar. Simulations based on the estimates suggest that the current Treasury Department proposal would lead to about a 30 percent increase in IRA contributions.
Moving and Housing Expenditure: Transaction Costs and Disequilibrium
The paper emphasizes initially the effects of moving transaction costs on the potential effect of government rent subsidy programs. As a concomitant to this analysis, the paper reaffirms the low income elasticities of housing expenditure among low-income renters found by others. Moving transaction costs are high on average among renters in our sample but vary widely between geographic regions and evidently vary a great deal among families as well. By our measure, transaction costs reflect monetary and especially non-monetary gains and losses associated with moving. Moving transaction costs in conjunction with low income elasticities make government lump-sum transfers very ineffective in increasing housing expenditure among low-incomerenters.A dollar of unconstrained transfer payment would increase housing expenditure by only 2 to 7 cents in the two cities in our data set. Minimum rent plans, that make the transfer payment conditional on spending at leasta minimum amount on rent, have larger effects on average than unconstrained transfers. Typical programs might increase rent by 10 to 30 cents per dollar of transfer payment. But families who spend the least on rent a real so those least likely to benefit from the minimum rent programs. To obtain payments under these plans, families who would otherwise spend less than the minimum must surmount the transaction costs associated with moving and must also reallocate income to favor housing in proportions that may be far from their preferred allocations. Thus only a small proportion of families with initial market rents below the minimum will ultimately participate in the programs. And of the total payments to these families, 15 to 32 percent is dead weight loss, according to our estimates. In addition, we find that because moving transaction costs and income elasticities vary widely among regions, the effects of any given government program are also likely to vary greatly from one region to the other.As a fortuitous benefit of the housing allowance demand experiment data that we used, we were also able to check our model results against experimental results. The model predictions and the experimental results correspond quite closely. The differences that are found can apparently be explained in large part by the impact of self-selection on the estimated experimental treatment effects. The self-determination of enrollment and the attrition inherent in the estimated experimental effects seriously detract from the potential benefits of experimental randomization. Therefore our model estimates may be more reliable than the experimental ones in this instance. Of course this judgment depends in large part on the experiment having been done so that we could check our model predictions against the experimental outcomes.
Aging and Housing Equity: Another Look
Aside from Social Security and, for some, employer-provided pensions, housing equity is the principle asset of a large fraction of older Americans. Many retired persons have essentially no financial assets to support retirement consumption. We use data from the Health and Retirement Study (HRS), the Asset and Health Dynamics Among the Oldest Old (AHEAD), and the Survey of Income and Program Participation (SIPP) to understand the extent to which families use housing equity to support general consumption in retirement. The initial analysis is based on self-assessed home values reported by survey respondents. Because the self-assessments exaggerate actual home equity, much of the subsequent analysis is based on the selling price of recently sold homes, together with the reported equity in recently purchased homes. Homeowners can change home equity by either discontinuing ownership or by purchasing another home of lesser or greater value. We find that in the absence of a precipitating shock--death of a spouse or entry of a family member into a nursing home- -families are unlikely to discontinue home ownership. And even when there is a precipitating shock, discontinuing ownership is the exception rather than the rule. On average, families that move and purchase a new home tend to increase home equity. We find, however, that income-poor and house-rich families are more likely to reduce equity when they move, while house-poor and income-rich households are more likely to increase housing equity. Overall, accounting for discontinuing ownership and moving to another home, housing equity increases with age until about age 75 and then declines slightly as households grow older. The overall decline among older households (surveyed in the AHEAD) is about 1.76 percent per year, and this decline is largely accounted for by a 7.84 percent decline among households who experience a precipitating shock. Families that remain intact reduce housing equity very little, about 0.11 percent per year for two-person households and 1.15 percent per year for one- person households. We conclude that, on average, home equity is not liquidated to support general non-housing consumption needs as households age.
- …