EVVMA and cusum control charts in the presence of correlation

The statistical properties of control charts are usually evaluated under the assumption that the observations from the process are independent. For many processes however, observations which are closely spaced in time will be correlated. This paper considers EWMA and CUSUM control charts for the process mean when the observations are from an AR(1) process with additional random error. This simple model may be a reasonable model for many processes encountered in practice. The ARL and steady state ARL of the EWMA and CUSUM charts are evaluated numerically using an integral equation approach and a Markov chain approach. The numerical results show that correlation can have a significant effect on the properties of these charts. Tables are given to aid in the design of these charts when the observations follow the assumed model.     

Conditional interval estimation of the mean following rejection of a two sided test

The effect of rejecting a two-sided preliminary test of significance for the mean of a normal distribution upon subsequent interval estimation of the mean is examined. For the case where the variance is known, conditional confidence intervals may be shorter than unconditional intervals, in contrast to the one-sided preliminary test case examined by Meeks and D’Agostino (1983, The American Statistician, 7, 134-136) . For the case where the variance is unknown and must be estimated by the sample variance, it is shown that customary intervals do not offer uniformly greater or lesser coverage than the nominal level.     

Mothers and child care: policies,values and theories

Government expansion of child care services is based on the assumption that both parents are employed (the adult worker model) and make cost‐benefit calculations in choosing child care (the rational economic choice model). This paper addresses this assumption, based on research examining mothers' assessments of appropriate child care. These assessments involve complex moral and emotional decisions around their own and their children's needs, and differ between social groups. On this basis, we conclude that the assumptions underlying current child care expansion policy are inadequate, and that the mere expansion of services is not enough.     

PAID- VERSUS DONATED-MEDIA STRATEGIES FOR PUBLIC SERVICE ANNOUNCEMENT CAMPAIGNS

Public service announcement (PSA) campaigns have traditionallyrelied on donated rather than paid advertising media. Recently,however, both government agencies and charitable or ganizationshave questioned whether donated-media strategies should be abandonedfor paid-media PSA campaigns. The present research examinesthis issue in a three-market field experiment comparing theeffectiveness of "paid versus donated" PSA cam paigns in decreasingyouthful male drinking and driving. Depen dent variables include(1) self-reports of behaviors from sample surveys and (2) officialcounts of incapacitating and fatal highway accidents. Resultsshow that both campaigns were equally effec tive and both werecost efficient. Thus, in light of these results, it is recommendedthat social marketers not abandon donated-media PSA campaignsfor paid-media PSA campaigns.     

Heterosexual Anal Intercourse among Men in Long Beach,California

Anal intercourse poses a greater risk for human immunodeficiency virus (HIV) transmission than vaginal intercourse, and in recent years there has been a growing understanding that heterosexual anal intercourse (HAI) is not uncommon. However, the majority of the anal intercourse literature has focused on men who have sex with men. The little research on HAI has mostly looked at women, with limited work among men. This analysis examined the association between HAI and high-risk behaviors (N = 1,622) and sexual sensation seeking (N = 239) in a sample of men recruited from 2001 to 2012 in Long Beach, California. Almost half of the sample was non-Hispanic Black. The median age was 42 years, 42% were homeless, and 20% reported recent HAI. Men who reported HAI were likely to be Hispanic, were likely to be homeless, had a male partner, engaged in sex exchange, and used cocaine or amphetamines during sex. Men who reported HAI scored higher on the Sexual Sensation Seeking scale. This research supports other work showing the relationship between HAI and high-risk behaviors. More important, it contributes new knowledge by demonstrating the association between HAI and sexual sensation seeking. This research highlights the importance of personality traits when trying to understand sexual behavior and when developing HIV prevention interventions.     

Music,rowing, and the aesthetics of rhythm

Having “good rhythm” is essential in both music and competitive rowing, but what exactly constitutes “good rhythm,” and how do we achieve it? Although rhythm is often discussed in purely auditory terms, I argue that rhythm is fundamentally a multisensory, kinesthetic phenomenon. By drawing parallels between music and rowing, I illustrate how biological motion principles underlie the parameters of rhythm in both disciplines, and how the cognition and appreciation of rhythm is deeply embodied. I suggest that the two main ways in which rhythms generate pleasure in both music and rowing are by enabling behavioral synchrony between individuals, and by engaging the body in the cognitive process of rhythm perception and prediction. In essence, “good rhythm”—a rhythm that is enjoyed and appreciated—is rhythm that moves.     

MEASURING CRACK COCAINE AND ITS IMPACT

Numerous social indicators turned negative for Blacks in the 1980s and rebounded a decade later. We explore whether crack cocaine explains these patterns. Absent a direct measure, we construct a crack prevalence index using multiple proxies. Our index reproduces spatial and temporal patterns described in ethnographic accounts of the crack epidemic. It explains much of the 1980s rise in Black youth homicide and more moderate increases in adverse birth outcomes. Although our index remains high through the 1990s, crack's deleterious social impact fades. Changes over time in behavior, crack markets, and the user population may have mitigated crack's damaging impacts. (JEL K42, J15, I30)