Monte carlo sampling approach to testing nonnested hypothesis: monte carlo results

Alternative ways of using Monte Carlo methods to implement a Cox-type test for separate families of hypotheses are considered. Monte Carlo experiments are designed to compare the finite sample performances of Pesaran and Pesaran's test, a RESET test, and two Monte Carlo hypothesis test procedures. One of the Monte Carlo tests is based on the distribution of the log-likelihood ratio and the other is based on an asymptotically pivotal statistic. The Monte Carlo results provide strong evidence that the size of the Pesaran and Pesaran test is generally incorrect, except for very large sample sizes. The RESET test has lower power than the other tests. The two Monte Carlo tests perform equally well for all sample sizes and are both clearly preferred to the Pesaran and Pesaran test, even in large samples. Since the Monte Carlo test based on the log-likelihood ratio is the simplest to calculate, we recommend using it.     

Marriage selection and age patterns of mortality: a mathematical investigation

"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."     

Genetic screening technology: ethical issues in access to tests by employers and health insurance committees

Whereas the introduction of new technologies previously has raised the ethical question of who ought to have access to a new procedure or device, genetic testing technology raises the new ethical question of to whom access to a new technology ought to be limited. In this article we discuss the implications of employers and private health insurance companies having access to genetic testing technology. Although there may be legitimate business interests in allowing employers and insurers to conduct genetic screening, there are other valid societal interests in regulating or limiting the use of this technology by third parties. Public policy developed in the area of new genetic technology must reflect such interests.     

Net worth and the economic diversity of the elderly

Using data from the 1984 panel of the Survey of Income and Program Participation (SIPP), this article examines characteristics of the older population disaggregated by net-worth quintiles. The authors argue that income is not a sufficient measure of economic status for current policy discussions on issues such as changing Medicare co-payments, increasing the taxation of social security benefits, or means-testing under Medicaid. Net worth is a better measure of economic status, particularly for the elderly, because it represents the net value of assets accumulated over the life course. Their results indicate that there is considerable diversity in the economic status of the older population, which is masked by aggregate statistics (such as means and medians) typically used to summarize the economic status of population groups. Stereotypical views of the elderly based on such aggregates result in misdirected policy formulation. In the future, policymakers will need to formulate policies and programs using information on the distributions of income and assets among the older populations rather than relying on statistical aggregates.     

Subsidized elderly housing: public-private partnerships on the brink

Starting in the early 1960s, the federal government joined with the private-sector housing developers in a partnership: in return for subsidized mortgages and tax benefits, developers would rent to low- and moderate-income tenants. Today, many elderly people live in these "publicly subsidized" units. The initial agreement, however, held out an escape clause: after 15 to 20 years, for-profit developers that wanted to end the partnership could prepay their mortgages, leaving tenants in those buildings "at risk" of rent increases and/or evictions. This article discusses that partnership, its options for dissolution, and the current solutions to the problem of the expiring agreements, including a moratorium, vouchers, and incentives. The compromise legislation responds to all interested parties--owners, current and would-be tenants, local governments, tax-payers--through a multi-stage sequence of dissolution, yet such a finely tuned, acutely sensitive legislative solution may not work easily or efficiently.     

Comparability of the 6-min walk test using different test configurations

The 6-min walk test (6MWT) is a common component of fitness assessments of older adults; however, differing course configurations might affect 6MWT performance. It is unclear how comparable 2 different configurations are. To determine the comparability of 2 courses, 35 adults >65 years of age completed two 6MWT, once walking around a 20- by 5-yd outdoor rectangle and once on an indoor oval track (circumference 144.3 yd). Scores for the 2 tests were internally consistent (intraclass correlation coefficient = .95). The participants walked farther on the oval track than around the rectangle (639 +/- 19 vs. 582 +/- 16 yd; p < .0001), but responses to the rectangular configuration could be readily estimated using the equation 66.7 yd + 0.807 x (oval walking distance), R2 = .85. Thus, within-participant responses are similar across both 6MWT, but the course configuration affects the distance walked.     

Does the impact of anti-drinking and driving Public Service Announcements differ based on message type and viewer characteristics?

The purpose of this study was to inform future Public Service Announcement (PSA) development by examining the potential effectiveness of different types of anti-driving under the influence (DUI) PSAs for persons with different characteristics. PSAs utilizing empathy, fear, and informational approaches were shown to persons recruited from psychology courses (n = 137) and individuals that were mandated to treatment following a DUI offense (n = 17). The empathy approach was perceived to be the most effective and evoked the most negative affect, followed by fear and informational approaches. Less experience with DUI, lower sensation seeking, higher motivation to change, and higher perception of dangerousness of DUI all emerged as good predictors of higher perceived effectiveness of anti-DUI PSAs. Gender differences in perceived effectiveness were examined for fear and empathy PSAs, with inconclusive findings.