Principal component and correspondence analysis of compositional data: some similarities

Principal component and correspondence analysis can both be used as exploratory methods for representing multivariate data in two dimensions. Circumstances under which the, possibly inappropriate, application of principal components to untransformed compositional data approximates to a correspondence analysis of the raw data are noted. Aitchison (1986) has proposed a method for the principal component analysis of compositional data involving transformation of the raw data. It is shown how this can be approximated by a correspondence analysis of appropriately transformed data. The latter approach may be preferable when there are zeroes in the data.     

School performance, academic aspirations, and drug use among children and adolescents

The relationship between drug use, school performance, and academic aspirations among 446 Anglo and Hispanic youths, age nine to seventeen, is explored. Two groups of subjects--current substance users and non-users--were interviewed. Subjects in each comparison group were similar in age, ethnicity, and gender. Overall results, consistent with prior research, indicate a significant relationship between current school performance, future educational aspirations, and drug use. No difference was noted between substance use groups on indicators of general interest in school work or probability of dropping out of school. Important differences in response patterns occurring with age, ethnicity, and gender were found.     

The therapist at play and the patient who begins to play

This paper addresses the therapeutic challenge presented in the initial phase of therapy by patients who have trouble playing and dreaming, that is, patients who use action-discharge and concrete communication and who show a relative lack of derivative, symbolic communication. An approach is described which conceptualizes therapy as taking place in an intermediate area between inner and outer reality, and in which playing, dreaming and interpretable transference, the vehicles of therapeutic work, can be facilitated. There can be advantages, in some cases, of using such an approach in family sessions. Clinical material is presented from the treatment of an adolescent in her family.     

Intrinsic Growth Rates and Net Reproduction Rates in the Presence of Migration

Conventional measures of long‐term population growth such as the intrinsic growth rate and the net reproduction rate assume migration rates to be zero. We develop expressions for analogous measures that register the impact of net migration rates, and we develop a simple method of estimating their values. Applying these new measures to data for developed countries shows that allowance for migration raises net reproduction rates by 0.2‐0.3 in areas of overseas European settlement and by approximately half as much in Northern and Western Europe. The newly defined intrinsic growth rates in Eastern Europe are exceptionally low at ‐1.7 percent to ‐2.4 percent per annum. In contrast, the migration‐adjusted intrinsic growth rate of the United States exceeds those of Asia and Latin America. The formulas and estimation procedures described should allow a more precise understanding of the implications of current migration patterns for long‐term growth prospects.     

Autonomy,diversity, and dissent: Conceptions of power and sources of action in the Sejarah Melayu (Raffles MS 18)

This study is concerned with exploring pre-colonial Malay ideas about power— about relationships between people and those who sought authority over them — and about the sources of social action and identity in pre-colonial Malay political culture. It examines, as its principal source for information about these issues, the Sejarah Melayu (Raffles MS 18), identifying significant instances in the text of dissent and of pluralism in Malay political culture.     

Investment in Shared Suppliers: Effect of Learning,Spillover, and Competition

We investigate the optimal strategies for firms to invest in their suppliers when the benefits of such investments can spillover to other firms who also source from the same suppliers. We consider two Bayesian firms that can invest in improving the quality of their shared supplier; the firms do not have complete information on the true quality of the supplier, but they update their beliefs based on the supplier's performance. We formulate the problem as an investment game and obtain Markov perfect equilibria characterized by the investment thresholds of both firms. The equilibrium investment strategies of the two firms are characterized by a region of preemption and a region of war of attrition. We also examine how the interplay between spillover, competition, and returns from the investment at shared suppliers affect the investment threshold and the time to the leader's investment, and identify the conditions under which competition delays or hastens the first investment in a shared supplier.     

Perception of Multisensory Gender Coherence in 6‐ and 9‐Month‐Old Infants

One of the most salient social categories conveyed by human faces and voices is gender. We investigated the developmental emergence of the ability to perceive the coherence of auditory and visual attributes of gender in 6‐ and 9‐month‐old infants. Infants viewed two side‐by‐side video clips of a man and a woman singing a nursery rhyme and heard a synchronous male or female sound track. Results showed that 6‐month‐old infants did not match the audible and visible attributes of gender, and 9‐month‐old infants matched only female faces and voices. These findings indicate that the ability to perceive the multisensory coherence of gender emerges relatively late in infancy and that it reflects the greater experience that most infants have with female faces and voices.     

Self‐conscious Shyness: Growth during Toddlerhood,Strong Role of Genetics,and No Prediction from Fearful Shyness

Fearful and self‐conscious subtypes of shyness have received little attention in the empirical literature. Study aims included the following: (1) determining whether fearful shyness predicted self‐conscious shyness, (2) describing development of self‐conscious shyness, and (3) examining genetic and environmental contributions to fearful and self‐conscious shyness. Observed self‐conscious shyness was examined at 19, 22, 25, and 28 months in same‐sex twins (MZ = 102, DZ = 111, missing zygosity = 3 pairs). Self‐conscious shyness increased across toddlerhood, but onset was earlier than predicted by theory. Fearful shyness (observed [6 and 12 months] and parents’ reports [12 and 22 months]) was not predictive of self‐conscious shyness. Independent genetic factors made strong contributions to parent‐reported (but not observed) fearful shyness (additive genetic influence = .69 and .72 at 12 and 22 months, respectively) and self‐conscious shyness (additive genetic influence = .90 for the growth model intercept). Results encourage future investigation of patterns of change and inter‐relations in shyness subtypes.