Race and the beauty premium: Mechanical Turk workers’ evaluations of Twitter accounts

ABSTRACT

Race, gender, and physical attractiveness strongly affect perceptions of trustworthiness and subsequent face-to-face interactions. This study examines how social media users’ perceived gender, race, and physical attractiveness can impact their standing online. We test these broad hypotheses by having Amazon Mechanical Turk (MTurk) workers evaluate a sample of 816 Twitter accounts. Our results show a ‘beauty premium,’ where MTurk workers say they are more likely to follow Twitter accounts with attractive pro?le photos, and attractive photos are positively associated with evaluations of trust. However, very attractive Black male and female Twitter accounts are associated with lower evaluations of trust compared to their White counterparts. These findings suggest that social media users’ social characteristics, perceived from their username or profile image, can replicate offline inequality online.     

A note on the changing relationship between fertility and female employment rates in developed countries

In this paper we look at a panel of OECD aggregate fertility and labor market data between 1970 and 1995 and we report some striking recent developments. Total Fertility Rates (TFR) were falling and Female Participation Rates (FPR) were increasing, conforming to a well known long-run trend. Along the cross-sectional dimension, the correlation between TFR and FPR was negative and significant during the 1970's and up to the early 1980's. This seemed consistent with secular comovements. However, by the late 1980's the correlation had become positive and equally significant. We discuss our findings within the framework of standard neoclassical models of fertility and labor supply adapted to macro data, as in Butz and Ward (1979). Received: 14 April 2000/Accepted: 29 December 2000 All correspondence to Pedro Mira. Namkee Ahn is grateful for financial support received from the Bank of Spain and from Spain's Ministerio de Educación y Cultura, grant SEC97-1249. We benefited from comments by two anonymous referees and by seminar participants at FEDEA, CEMFI and ESPE-98. All remaining errors are our own. Responsible editor: John F. Ermisch.     

Five new towns in the Seoul metropolitan area and their attractions in non-working trips: Implications on self-containment of new towns

In the late 1980s, the Korean government initiated the “Two Million Home Construction Plan” to tackle severe shortages in housing and soaring housing prices. Five new towns (Bundang, Ilsan, Pyeongchon, Sanbon, and Joongdong) were planned around the city of Seoul. By the mid-1990s the residential areas in the five new towns were mostly developed. However, their commercial areas have remained underdeveloped and as a consequence, the new towns are believed to have become bedroom communities.This paper assesses self-containment status of the new towns by analyzing non-working trip patterns in the five new town areas. A survey conducted on non-working trip patterns of the residents in the five new towns and the nearby areas (to shop for groceries, clothing, electronics/jewelry, leisure/entertainment, and to access medical services) reveals that Bundang's commercial dependency upon the city of Seoul has been reduced significantly over the past 5 years (from 1995 to 2000). The survey results on non-working trip patterns of the residents in the five new towns and nearby residential areas in the Seoul Metropolitan Area indicate that the five new towns have been growing as suburban centers in the region in terms of retail attractions, even though they are still maintaining a high dependency on Seoul in terms of working commutes.These observations provide some new indications about self-containment arguments relevant to new town planning. The new towns are currently maintaining a decent degree of self-containment in terms of non-working trip, which has been an important aspect absent in self-containment arguments. In addition, the appeal of self-containment in non-working activities is growing in a dynamic sense. Observations on the dynamic process of the new town developments in Korea demonstrate that the self-containment can be established but through a long taking cumulative and stepwise process rather than immediately by planning.     

Eigenvalue Ratio Test for the Number of Factors

This paper proposes two new estimators for determining the number of factors (r) in static approximate factor models. We exploit the well‐known fact that the r largest eigenvalues of the variance matrix of N response variables grow unboundedly as N increases, while the other eigenvalues remain bounded. The new estimators are obtained simply by maximizing the ratio of two adjacent eigenvalues. Our simulation results provide promising evidence for the two estimators.     

Attribution of tumour lethality and estimation of the time to onset of occult tumours in the absence of cause-of-death Information

A new statistical approach is developed for estimating the carcinogenic potential of drugs and other chemical substances used by humans. Improved statistical methods are developed for rodent tumorigenicity assays that have interval sacrifices but not cause-of-death data. For such experiments, this paper proposes a nonparametric maximum likelihood estimation method for estimating the distributions of the time to onset of and the time to death from the tumour. The log-likelihood function is optimized using a constrained direct search procedure. Using the maximum likelihood estimators, the number of fatal tumours in an experiment can be imputed. By applying the procedure proposed to a real data set, the effect of calorie restriction is investigated. In this study, we found that calorie restriction delays the tumour onset time significantly for pituitary tumours. The present method can result in substantial economic savings by relieving the need for a case-by-case assignment of the cause of death or context of observation by pathologists. The ultimate goal of the method proposed is to use the imputed number of fatal tumours to modify Peto's International Agency for Research on Cancer test for application to tumorigenicity assays that lack cause-of-death data.     

A proportional-reduction-in-impurity measure of association for categorical variables

This paper presents a proportional-reduction-in-impurity (PRI) measure for categorical association, that employs application-dependent loss functions which make the measure widely applicable. The well-known proportional -reduction-in-error (PRE) measure is shown to be a special case of the new PRI measure. Moreover, the asymptotic variance of the maximum likelihood estimator (MLE) of the measure is derived to facilitate its use for statistical inference. An extension of the PRI measure to compositional association is made to show that it can have a variety of applications. Selected loss functions are treated to illustrate the derivation of the measure.     

Efficient Markov chain Monte Carlo with incomplete multinomial data

We propose a block Gibbs sampling scheme for incomplete multinomial data. We show that the new approach facilitates maximal blocking, thereby reducing serial dependency and speeding up the convergence of the Gibbs sampler. We compare the efficiency of the new method with the standard, non-block Gibbs sampler via a number of numerical examples.     

Modified regression coefficient analysis for repeated binary measurements

Myers & Broyles (2000a, 2000b) illustrate that regression coefficient analysis (RCA) is a viable alternative to a generalized estimating equation (GEE) in the analysis of correlated binomial data. Since the regression coefficients (b i ' s ) may have different precisions, we modify RCA by weighting b i ' s by the inverses of their variances for statistical optimality. We perform the simulation study to evaluate the performance of RCA, modified RCA and GEE in terms of empirical type I errors and empirical powers of the regression coefficients in repeated binary measurement designs with and without dropouts. Two thousand data sets are generated using autoregressive (AR(1)) and compound symmetry (CS) correlation structures. We compare the type I errors and powers of RCA, modified RCA and GEE for the analysis of repeated binary measurement data as affected by different dropout mechanisms such as random dropouts and treatment dependent dropouts.