The Development of Anticipatory Smiling

When do infants begin to communicate positive affect about physical objects to their social partners? We examined developmental changes in the timing of smiles during episodes of initiating joint attention that involved an infant gazing between an object and a social partner. Twenty‐six typically developing infants were observed at 8, 10, and 12 months during the Early Social‐Communication Scales, a semistructured assessment for eliciting initiating joint attention and related behaviors. The proportion of infant smiling during initiating joint attention episodes did not change with age, but there was a change in the timing of the smiles. The likelihood of infants smiling at an object and then gazing at the experimenter while smiling (anticipatory smiling) increased between 8 and 10 months and remained stable between 10 and 12 months. The increase in the number of infants who smiled at an object and then made eye contact suggests a developing ability to communicate positive affect about an object.     

Goodness‐of‐fit methods for matched case‐control studies

The authors propose graphical and numerical methods for checking the adequacy of the logistic regression model for matched case‐control data. Their approach is based on the cumulative sum of residuals over the covariate or linear predictor. Under the assumed model, the cumulative residual process converges weakly to a centered Gaussian limit whose distribution can be approximated via computer simulation. The observed cumulative residual pattern can then be compared both visually and analytically to a certain number of simulated realizations of the approximate limiting process under the null hypothesis. The proposed techniques allow one to check the functional form of each covariate, the logistic link function as well as the overall model adequacy. The authors assess the performance of the proposed methods through simulation studies and illustrate them using data from a cardiovascular study.     

An empirical examination of cost-adjusting in outpatient clinics

This paper presents an empirical methodology for examining cost-adjusting in relation to multiple-output health care providers. The methodology is subsequently implemented using a sample of California outpatient clinics. The empirical evidence is that these clinics do cost-adjust; that is, the clinics respond to low Medicare reimbursement by using lower quality to control the marginal costs of those patient groups not insured under a government-sponsored plan. In addition, clinics do not cost-adjust with respect to Medi-Cal patients, implying that various government reimbursement systems have different effects on a provider’s cost-adjusting behavior.     

A Bayesian Hierarchical Model for the Evaluation of a Website

Consider a website and the surfers visiting its pages. A typical issue of interest, for example while monitoring an advertising campaign, concerns whether a specific page has been designed successfully, i.e. is able to attract surfers or address them to other pages within the site. We assume that the surfing behaviour is fully described by the transition probabilities from one page to another, so that a clickstream (sequence of consecutively visited pages) can be viewed as a finite-state-space Markov chain. We then implement a variety of hierarchical prior distributions on the multivariate logits of the transition probabilities and define, for each page, a content effect and a link effect. The former measures the attractiveness of the page due to its contents, while the latter signals its ability to suggest further interesting links within the site. Moreover, we define an additional effect, representing overall page success, which incorporates both effects previously described. Using WinBUGS, we provide estimates and credible intervals for each of the above effects and rank pages accordingly.     

Glass ceilings or sticky floors? A model of high-income law graduates

Minorities and females are underrepresented in the top-income quintile of law school graduates. Employing a binary logistic regression model, I examine whether this is due to a“glass ceiling” (an invisible barrier erected by third parties) or a“sticky floor” (self-imposed limitations regarding employment). My major finding is that being female, a minority, or disabled did not significantly reduce one's probability of making the top-income quintile once hours of work, experience, and other factors are taken into account. My findings directly contradict the large body of glass-ceiling literature and support the sticky-floor model. I thank the Law School Admission Council for funding this research. Helpful comments and suggestions were received from Robert Nelson of Northwestern University and the American Bar Foundation, Steven Conroy of the University of West Florida, and R. Kim Craft and Douglas Bonzo of Southern Utah University. The views expressed here are solely those of the author and do not necessarily reflect those of the institutions or persons listed above.     

CORPORATE TAX INCIDENCE AND INEFFICIENCY WHEN CORPORATE AND NONCORPORATE GOODS ARE CLOSE SUBSTITUTES

An important deficiency in Harberger's [1962] model of corporate income taxation is its inability to consider both corporate and noncorporate production of the same good. Within-industry substitution has potentially major implications for both the excess burden and incidence of the corporate tax.
We analyze this within-industry substitution using a model in which each industry/sector contains corporate and noncorporate firms (with identical production functions) which produce goods that are close substitutes. The scope for considerable within-industry substitution of noncorporate for corporate capital leads to a very much larger excess burden than that in the Harberger model.     

Adoptive parents to children with severe developmental disabilities: A profile

A sample of 16 women and men who accompanied their adopted children with severe developmental disabilities to a medical appointment at Henry Ford Hospital's Multidisciplinary Care Clinic during the one-year period beginning July 1, 1988 are described in the context of their parental role vis-a-vis these children. Results of the study are presented through use of a six-part organizational scheme: demographic and social traits of the parents and their adopted children, the adopted children in family context, life satisfactions of the parents, adoption motives, adoption satisfactions, and humanization of the children.