Showing papers by "University of Chicago published in 1986"

Fractal measures and their singularities: The characterization of strange sets

Abstract: We propose a description of normalized distributions (measures) lying upon possibly fractal sets; for example those arising in dynamical systems theory. We focus upon the scaling properties of such measures, by considering their singularities, which are characterized by two indices: \ensuremath{\alpha}, which determines the strength of their singularities; and f, which describes how densely they are distributed. The spectrum of singularities is described by giving the possible range of \ensuremath{\alpha} values and the function f(\ensuremath{\alpha}). We apply this formalism to the ${2}^{\ensuremath{\infty}}$ cycle of period doubling, to the devil's staircase of mode locking, and to trajectories on 2-tori with golden-mean winding numbers. In all cases the new formalism allows an introduction of smooth functions to characterize the measures. We believe that this formalism is readily applicable to experiments and should result in new tests of global universality.

Sequence and expression of human estrogen receptor complementary DNA

Abstract: The mechanism by which the estrogen receptor and other steroid hormone receptors regulate gene expression in eukaryotic cells is not well understood. In this study, a complementary DNA clone containing the entire translated portion of the messenger RNA for the estrogen receptor from MCF-7 human breast cancer cells was sequenced and then expressed in Chinese hamster ovary (CHO-K1) cells to give a functional protein. An open reading frame of 1785 nucleotides in the complementary DNA corresponded to a polypeptide of 595 amino acids and a molecular weight of 66,200, which is in good agreement with published molecular weight values of 65,000 to 70,000 for the estrogen receptor. Homogenates of transformed Chinese hamster ovary cells containing a protein that bound [3H]estradiol and sedimented as a 4S complex in salt-containing sucrose gradients and as an 8 to 9S complex in the absence of salt. Interaction of this receptor-[3H]estradiol complex with a monoclonal antibody that is specific for primate ER confirms the identity of the expressed complementary DNA as human estrogen receptor. Amino acid sequence comparisons revealed significant regional homology among the human estrogen receptor, the human glucocorticoid receptor, and the putative v-erbA oncogene product. This suggests that steroid receptor genes and the avian erythroblastosis viral oncogene are derived from a common primordial gene. The homologous region, which is rich in cysteine, lysine, and arginine, may represent the DNA-binding domain of these proteins.

Chapter 12 The theory of equalizing differences

Abstract: Publisher Summary The chapter presents a discussion on the theory of equalizing differences. The theory of equalizing differences refers to observed wage differentials required to equalize the total monetary and nonmonetary advantages or disadvantages among work activities and among workers themselves. On the conceptual level, it can make legitimate claim to be the fundamental (long-run) market equilibrium construct in labor economics. Its empirical importance lies in contributing useful understanding to the determinants of the structure of wages in the economy and for making inferences about preferences and technology from observed wage data. Measurable job attributes on which compensating wage differentials have been shown to arise empirically include (1) onerous working conditions, such as risks to life and health, exposure to pollution, and so forth; (2) intercity and interregional wage differences associated with differences in climate, crime, pollution, and crowding; (3) special work-time scheduling and related requirements, including shift work, inflexible work schedules, and possible risks of layoff and subsequent unemployment; and (4) the composition of pay packages, including vacations, pensions, and other fringe benefits as substitutes for direct cash wage payments. Another important class of problems identifies work environments with investment rather than with consumption. Market equilibrium is defined by equality between demand and supply for workers on each type of job.

On Lova´sz' lattice reduction and the nearest lattice point problem

Abstract: Answering a question of Vera Sos, we show how Lovasz’ lattice reduction can be used to find a point of a given lattice, nearest within a factor ofc d (c = const.) to a given point in R d . We prove that each of two straightforward fast heuristic procedures achieves this goal when applied to a lattice given by a Lovasz-reduced basis. The verification of one of them requires proving a geometric feature of Lovasz-reduced bases: ac 1 lower bound on the angle between any member of the basis and the hyperplane generated by the other members, wherec 1 = √2/3. As an application, we obtain a solution to the nonhomogeneous simultaneous diophantine approximation problem, optimal within a factor ofC d . In another application, we improve the Grotschel-Lovasz-Schrijver version of H. W. Lenstra’s integer linear programming algorithm. The algorithms, when applied to rational input vectors, run in polynomial time.

Chapter 2 Female labor supply: A survey

Abstract: Publisher Summary This chapter presents a survey on female labor supply. The chapter surveys theoretical and empirical work on the labor supply of women, with special reference to women in Western economies, primarily the United States, in modern times. The behavior of female labor supply has important implications for many other phenomena, including marriage, fertility, divorce, the distribution of family earnings and male-female wage differentials. The labor supply of women is also of interest, because of the technical questions it poses. For example, because many women do not work, corner solutions are at least potentially a very important issue in both the theoretical and empirical analysis of female labor supply, even though in other contexts (for example, studies of consumer demand) corner solutions are often ignored. The chapter presents some “stylized facts” about female labor supply, and then discusses a number of theoretical models of special interest for understanding female labor supply. After considering empirical studies of the labor supply of women, the chapter concludes with some suggestions for future research. The chapter discusses major trends and cyclical patterns in time-series data, and then examines cross-sectional phenomena.

Consumer Learning: Advertising and the Ambiguity of Product Experience

Abstract: This paper examines the influence of advertising on how and what consumers learn from product experience. A hypothesis-testing framework is adopted where consumers treat advertisements as tentative hypotheses that can be tested through product experience. Two experiments were conducted using product categories that provided either ambiguous or unambiguous evidence about product quality. The first experiment showed that when consumers have access to unambiguous evidence, judgments of product quality are dependent only on the objective physical evidence and unaffected by advertising. However, advertising had dramatic effects on perceptions of quality when consumers saw ambiguous evidence; judgments and product inspection behavior protocols showed that advertising induced consumers to engage in confirmatory hypothesis testing and search. The second experiment showed that advertising influenced quality judgments by affecting the encoding of the physical evidence; retrieval of ad-consistent evidence also appeared to occur, though to a lesser degree.

Judging probable cause.

Abstract: Les auteurs ont passe en revue et complete diverses theories de la causalite proposees par des psychologues, des philosophes, des statisticiens et d'autres auteurs, cherchant a expliquer les processus qui sous-tendent le jugement de causalite

Bayesian Estimation and Prediction Using Asymmetric Loss Functions

Abstract: Estimators and predictors that are optimal relative to Varian's asymmetric LINEX loss function are derived for a number of well-known models. Their risk functions and Bayes risks are derived and compared with those of usual estimators and predictors. It is shown that some usual estimators, for example, a scalar sample mean or a scalar least squares regression coefficient estimator, are inadmissible relative to asymmetric LINEX loss by providing alternative estimators that dominate them uniformly in terms of risk.

Chapter 10 Wage determinants: A survey and reinterpretation of human capital earnings functions

Abstract: Publisher Summary The chapter presents a survey and exposition of the development of the earnings function as an empirical tool for the analysis of the determinants of wage rates. Generically, the term “earnings function” has come to mean any regression of individual wage rates or earnings on a vector of personal, market, and environmental variables thought to influence the wage. The premier application is to the study of the effects of investment in schooling and on-the-job training on the level, pattern, and interpersonal distribution of life cycle earnings associated with the pioneering work on human capital by several mentioned scholars. The chapter is devoted to the theoretical and empirical development of the human capital earnings function during the past 25 years. The chapter surveys the empirical estimates of the rate of return to education and the pattern of life cycle earnings. The chapter discusses the derivation of human capital earnings functions under the assumption of homogenous human capital and introduces the model of heterogeneous human capital described. The chapter considers theoretical and econometric issues, which arise when there is inequality of opportunity and ability and closes with a discussion of empirical findings concerning ability bias. The chapter also describes some recent literature on several topics such as signalling, implicit contracts, and specific human capital, which extend or modify certain aspects of the human capital model.

Factorial and Discriminant Validity of the Center for Epidemiological Studies Depression (CES-D) Scale.

Abstract: The factorial and discriminant validity of the Center for Epidemiological Studies Depression (CES-D) scale was examined for a sample of 116 parents who were participating in family support programs designed to prevent child abuse and neglect. Participants' self-reports of depressive symptoms as measured by the CES-D were analyzed in relation to their self-esteem (measured with the Rosenberg Self-Esteem scale) and state and trait anxiety (measured with Spielberger's State-Trait Anxiety Inventory). Factorial validity was adequate, and results indicated a moderate correlation between the CES-D and self-esteem and state anxiety. However, a high correlation was obtained between the CES-D and trait anxiety, which suggests that the CES-D measures in large part the related conceptual psychological domain of predisposition for anxiousness.

The Rigidity of Prices

Abstract: This paper presents evidence on the amount of price rigidity that exists in individual transaction prices Using the Stigler-Kindahi data, I examine the behavior of individual buyers' prices for certain products used in manufacturing My most important findings are: 1The degree of price rigidity in many industries is significant It is not unusual in some industries for prices to individual buyers to remain unchanged for several years 2Even for what appear to be homogeneous commodities, the correlation of price changes across buyers is very low 3There is no evidence that there is an asymmetry in price rigidity In particular, prices are not rigid down-ward 4The fixed costs of changing price at least to some buyers seem trivial There are plenty of instances where small price changes occur 5The level of industry concentration is strongly correlated with rigid prices The more concentrated the industry, the longer is the average spell of price rigidity 6There appears to be a relationship between price rigidity, size of price change, and the length of time a buyer and seller deal with each otherI interpret the findings as evidence that it is erroneous to focus attention on price as the exclusive mechanism to allocate resources Nonprice rationing is not a fiction, it is a reality of business and may be the efficient response to economic uncertainty

Evidence evaluation in complex decision making.

Abstract: This study investigates the role of representation of evidence in a juror's decision process. A model is presented that includes an initial stage of processing in which cognitive representations of the evidence in the form of stories are produced. This is followed by a computation of the decision by evaluating the goodness-of-fit of the evidence representation (story) to the verdict categories. Subjects, drawn from jury pools, made individual decisions on the verdicts for a filmed murder trial. Extensive interviews provided the data for analysis of their cognitive representations of the evidence in the case, the verdict categories presented in the trial judge's instructions, and the procedures they were to follow according to law to reach a verdict. We found, as hypothesized, that the trial evidence was represented in a story form. Furthermore, differences among jurors in cognitive representations of evidence were correlated with their verdicts, although other aspects of the decision process (verdict category representations, application of the standard of proof procedural instruction) were not. We conclude that adequate theories of decision making must emphasize cognitive aspects of performance, such as the representation of evidence.

The Transition to Adulthood

Abstract: An enonnous amount of research on the transition to adulthood in America is founded on early landmark studies that include Elmtown' S Youth by August B. Hollingshead (1961), The Adolescent Society by James Coleman (1961), and the report of the Presidential Panel on Youth ( 1974). Research culminating in what has become known as the Wisconsin model of status attainment focused attention on the transition to adulthood; the study found that social psycholog­ ical and institutional factors operating in adolescence mediated the effects of socioeconomic origins on educational attainment, occupational attainment, and e arnings (Sewell & Hauser 1975). More recently, concern with high levels of premarital adolescent pregnancy among blacks and rising levels among whites prompted a great many studies on the antecedents and consequences of a premature transition to parenthood (Chilman 1980). Similarly, high levels of youth unemployment stimulated investigation of the process by which young people make the transition to full-time worker (Stephenson 1979). Scholarly interest in changes in the family life course has led to research on historical changes in the transition to adulthood (Modell et a11976, Winsborough 1978, Hogan 1981). Researchers' work on labor markets and socioeconomic attain­ ments led to study of the nature of careers (Spenner et a11982, Elder 1985a ). At the same time, new and better techniques for the collection and analysis of event history data have been developed (Hannan & Tuma 1979). The transition from adolescent to adult has long been of interest to students of human development. During the period of adolescence, young people grow to their full adult size , undergo the hormonal and physical changes associated with puberty, and attain reproductive maturity. Piaget has defined the cognitive task of adolescence as the achievement of fonnal operational reasoning (see Mussen 1970, Keating 1980). Personality development during adolescence has been

Knowledge and Women's Interests: Issues of Epistemology and Methodology in Feminist Sociological Research*

Abstract: This analysis focuses on feminist methodology in the field of sociology by surveying the techniques used in recent research concerning gender-related topics as well as feminist analyses of epistemological assumptions underlying the conduct of inquiry. In addition to the critique and reformulation of standard research practice, feminist methodology involves the development of innovative methodological approaches, including visual techniques, conversational and textual analysis, and analysis of spontaneous events. Linked to the development of innovation is the feminist analysis of the epistemological assumptions which underlie different ways of knowing. These principles of feminist knowledge include (1) the necessity of continuously and reflexively attending to the significance of gender relations as a basic feature of all social life, including the conduct of research; (2) the centrality of consciousness-raising as a specific methodological tool and as a “way of seeing;” (3) the need to challenge the norm of “objectivity” that assumes a dichotomy between the subject and object of research; (4) the concern for the ethical implications of research; and (5) an emphasis on the transformation of patriarchy and the empowerment of women.

Viscous flows in two dimensions

Abstract: This review is an expository treatment of the displacement of one fluid by another in a two-dimensional geometry (a Hele-Shaw cell). The Saffman-Taylor equations modeling this system are discussed. They are simulated by random-walk techniques and studied by methods from complex analysis. The stability of the generated patterns (fingers) is studied by a WKB approximation and by complex analytic techniques. The primary conclusions reached are that (a) the fingers are linearly stable even at the highest velocities, (b) they are nonlinearly unstable against noise or an external perturbation, the critical amplitude for the noise being an exponential function of a power of the velocity for high velocities, (c) such exponentials seem to dominate high-velocity behavior, as can be seen from a WKB analysis, and (d) the results of the Saffman-Taylor equations disagree with experiments, apparently because they leave out film-flow phenomena.

Mathematics achievement of Chinese, Japanese, and American children

Abstract: American kindergarten children lag behind Japanese children in their understanding of mathematics; by fifth grade they are surpassed by both Japanese and Chinese children. Efforts to isolate bases for these differences involved testing children on other achievement and cognitive tasks, interviewing mothers and teachers, and observing children in their classrooms. Cognitive abilities of children in the three countries are similar, but large differences exist in the children's life in school, the attitudes and beliefs of their mothers, and the involvement of both parents and children in schoolwork.

Background and Mass Extinctions: The Alternation of Macroevolutionary Regimes

Abstract: Comparison of evolutionary patterns among Late Cretaceous marine bivalves and gastropods during times of normal, background levels of extinction and during the end-Cretaceous mass extinction indicates that mass extinctions are neither an intensification of background patterns nor an entirely random culling of the biota. During background times, traits such as planktotrophic larval development, broad geographic range of constituent species, and high species richness enhanced survivorship of species and genera. In contrast, during the, end-Cretaceous and other mass extinctions these factors were ineffectual, but broad geographic deployment of an entire lineage, regardless of the ranges of its constituent species, enhanced survivorship. Large-scale evolutionary patterns are evidently shaped by the alternation of these two macroevolutionary regimes, with rare but important mass extinctions driving shifts in the composition of the biota that have little relation to success during the background regime. Lineages or adaptations can be lost during mass extinctions for reasons unrelated to their survival values for organisms or species during background times, and long-term success would require the chance occurrence within a single lineage of sets of traits conducive to survivorship under both regimes.

A Time Series Analysis of Representative Agent Models of Consumption andLeisure Choice Under Uncertainty

Abstract: This paper investigates empirically a model of aggregate consumption and leisure decisions in which goods and leisure provide services over time. The implied time non-separability of preferences introduces an endogenous source of dynamics which affects both the co-movements in aggregate compensation and hours worked and the cross-relations between prices and quantities. These cross-relations are examined empirically using post-war monthly U.S. data on quantities, real wages and the real return on the one-month Treasury bill. We find substantial evidence against the overidentifying restrictions. The test results suggest that the orthogonality conditions associated with the representative consumer's intratemporal Euler equation underlie the failure of the model. Additionally, the estimated values of key parameters differ significantly from the values assumed in several studies of real business models. Several possible reasons for these discrepancies are discussed.