The New Beneficiary Data System: the first phase.

The completion of field work for the 1991 New Beneficiary Followup has transformed the 1982 New Beneficiary Survey from a simple cross-sectional data collection effort to the first step in a new longitudinal data base, which is further enriched with information obtained from administrative records. The resulting New Beneficiary Data System will make it possible to develop a better understanding of the dynamics of the experience of aged and disabled populations over the long term. A review of 24 reports prepared by Social Security Administration analysts who have used data from the first wave of interviews reveals a great deal of variation among different types of beneficiaries with respect to income, assets, pensions, work, health, and other factors. These reports provide a useful context for examining patterns of stability and change in the beneficiary population as the data from administrative records and later interviews are added to the data base and used to address issues of policy interest.

Asset holdings of the newly disabled: findings from the New Beneficiary Survey.

About 3 out of 4 new disabled-worker beneficiaries or their spouses owned some type of financial asset in 1982, but the median value of these assets was quite small, according to data obtained by the Social Security Administration in its New Beneficiary Survey. A smaller majority reported owning their own homes, and home equity accounted for most of the reported wealth. Barely a tenth reported that they owned farms, businesses, or commercial property. Differences in age and marital status within the newly disabled population were associated with large differences in asset holdings. Married couples and older disabled workers generally were more likely to own each kind of asset, and generally reported higher values for these assets. Older married men--the largest subgroup among the disabled--are also relatively well-off, though their median asset portfolios were worth only +3,600 when home equity was excluded. Younger single men, the third largest subgroup, reported median total assets worth less than +50, however home equity was treated. The asset ownership rates and median values reported by the new disabled-worker beneficiaries are much lower for every type of asset considered than the rates and values reported by a comparable sample of new retired-worker beneficiaries.

The issue unresolved: innovating and adapting disability programs for the third era of Social Security.

The history of the Social Security programs in the United States falls into several distinct eras, defined by changing social, demographic, and economic conditions. At present the retirement component of these programs is moving into a stage of program maturation, which poses certain relatively well-understood changes to policymakers. The disability programs are also moving into the same set of societal conditions, but their impact is considerably more difficult to predict. Already disability incidence rates have experienced disturbingly large and poorly understood shifts. Developing a way to predict these shifts and to deal with the challenges that they make for existing programs is therefore a major priority of Social Security's current research agenda.

The challenge of the 21st century: innovating and adapting Social Security systems to economic, social, and demographic changes in the English-speaking Americans.

The Social Security Programs in the United States are complex and have evolved over a long span of years. However, it is possible to categorize much of this experience into two different eras in which Social Security functioned in a distinctive environment, and a third era that is now beginning. The middle third of this century was an "age of invention," in which the programs grew rapidly under favorable social and economic conditions. Since then, the programs have experienced an "age of accommodation," in which growing financial constraints have permitted only limited changes in the program. We can look forward to an "age of maturation" in the decades to come, as most persons reaching retirement will have been covered by Social Security during their entire working careers. The declining ratio of workers to beneficiaries and a wide range of demographic and social changes will present significant challenges. The Social Security programs must change considerably to respond to the demands of a new era, and vigorous efforts to do so are underway.

Income of retirement-aged persons in the United States.

This article reviews the composition and level of retirement income in the United States and how this has changed over time, focusing on two overlapping but distinct groups--the entire population aged 65 or older, and recent retirees. Changes in the composition of income of the aged over the past 20-30 years, including greatly expanded Social Security and pension coverage and an increasing number of persons with retirement savings, have improved the economic status of the aged not only in comparison with the aged in earlier years, but also in comparison with younger adults who derive most of their income from earnings. New retired workers are better off than the total aged population in several respects. The younger cohorts now in the labor force will spend more of their working lives in the more favorable conditions now present than was true of past new beneficiaries or the aged as a whole. It is, therefore, not unreasonable to expect that today's workers will enjoy more and larger pensions and increased income from savings to supplement their Social Security benefits when they retire.

Women, marriage, and Social Security benefits.

The majority of women Social Security beneficiaries receive at least part of their benefit based on their status as the wives or widows of entitled workers. This article discusses the impact of past and present marital status of women as a factor in establishing eligibility for monthly benefits and the amount of the benefit payment. The data are drawn from the 1980 and 1985 June Marital History Supplements to the Current Population Survey. Whether or not they are currently receiving auxiliary benefits, most older women are potentially eligible for them based on their current marital status or past marital duration.

The Income Survey Development Program: design features and initial findings.

This article summarizes the principal design features of the Income Survey Development Program (ISDP) and presents initial findings of its 1979 Research Panel. The ISDP was designed to meet the need for improved data--particularly information on cash and in-kind income, assets and debts, tax liabilities, and participation in the major income security programs. The ISDP examined many technical and operational problems that were difficult to satisfy with existing surveys and administrative record systems. The ISDP field tests indicated that several experimental features were successful. These include use of more frequent interviews, a sample that is followed over a period of more than a year, a flexible questionnaire structure that permits insertion of questions on emerging policy issues, and procedures to maximize the linking of survey data with information in administrative records. Initial findings from the 1979 Research Panel indicate the number of persons receiving benefits from more than one major transfer program and compare the assets of food stamp recipients with those of eligible nonparticipants and ineligible persons.

On certain homologies between proteins.

Using, in part, comparisons between reconstructed ancestral sequences, homologies are suggested between certain proteins. Genetically related groups seem to be: 1. pancreatic and bacterial nucleases, 2. lysozymes and subtilisins, 3. c type cytochromes, ferredoxins and rubredoxins, 4. b type cytochromes, myoglobins and hemoglobins, catalase, and glutamic dehydrogenase. These homologies suggest that a given ancestral sequence can evolve into quite different tertiary structures.

Computing tertiary structures of proteins.

Using only data on sequence, a method of computing a low-resolution tertiary structure of a protein is described. The steps are: (a) Estimate the distances of individual residues from the centroid of the molecule, using data on hydrophobicity and additional geometrical constraints. (b) Using these distances, construct a two-valued matrix whose elements, the distances between residues, are greater or less than R, the radius of the molecule. (c) Optimize to obtain a three-dimensional structure. This procedure requires modest computing facilities and is applicable to proteins with 164 residues and presumably more. It produces structures with r (correlation between inter-residue distances in the computed and native structures) between 0.5 and 0.7. Furthermore, correct inference of two or three long-range contacts suffices to yield structures with r values of 0.8-0.9. Because segments forming parallel or antiparallel folding structures intersect the radius vector at similar angles, from centroidal point distances it is possible to infer some of these long-range contacts by an elaboration of the procedure used to construct the input matrix. A criterion is also described which can be used to determine the quality of a proposed input matrix even when the native structure is not known.

Origin of periodic proteins.

Certain proteins, of which collagen is the best known example, have an approximately periodic sequence of amino acids. Evidence is available that the nucleic acid templates of at least some of these proteins have a large amount of internal self-complementarity. It is difficult to explain the origin of such proteins from nonperiodic proteins by accumulation of single amino acid replacements. A saltatory origin is suggested; the process would be a repetitive replication of a small nucleic acid segment. Internal self-complementarity occurs because the repeating segment incorporates sequences from both strands of DNA. The same process could produce RNA with a large amount of internal self-complementarity; tRNA may be an example.

Codons and hypercycles.

Several hypotheses on the origin of codon assignments imply that the present protein synthesizing machinery was already in place when the assignments were made. These are examined by computer modeling. The results do not suggest that assignments were optimized for resistance to reading and mutation errors, nor that the assignments are random. It is improbable that the number of species of amino acids increased in the course of evolution. An originally ambiguous dictionary is likely to have been subject to error catastrophe and is improbable. A relation between amino acid properties and their codons exists, and suggests that the codon assignments were established at the time of origin of the hypercycle, i.e. a system of aminoacyl synthetases which attaches amino acids to tRNA, and before the present protein synthesizing machinery was in place. The origin of a hypercycle is only possible if the system began with components which were catalytically active even when they did not form a self-replicating system. A model of such a system is proposed.

The error catastrophe hypothesis and aging.

A theory of the propagation of errors in the system of enzymes translating genetic information into proteins developed earlier is extended to include errors at the transcription level. The theory is compared to other statistical theories. The properties are defined of the protein synthesizing machineries, especially those of the erroneous enzymes, which give catastrophe, stable self-replication containing errors, recovery from errors, etc. Experimental data are analyzed in light of the theory to determine the validity of the error catastrophe hypothesis of aging.