Productivity, Wages and Marriage: The Case of Major League Baseball

The effect of marriage on productivity and, consequently, wages has been long debated in economics. A primary explanation for the impact of marriage on wages has been through its impact on productivity, however, there has been no direct evidence for this. In this paper, we aim to fill this gap by directly measuring the impact of marriage on productivity using a sample of professional baseball players from 1871 - 2007. Our results show that only lower ability men see an increase in productivity, though this result is sensitive to the empirical specification and weakly significant. In addition, despite the lack of any effect on productivity, high ability married players earn roughly 16 - 20 percent more than their single counterparts. We discuss possible reasons why employers may favor married men.Productivity, wage gap, marriage, and baseball

A role for the developing lexicon in phonetic category acquisition

Infants segment words from fluent speech during the same period when they are learning phonetic categories, yet accounts of phonetic category acquisition typically ignore information about the words in which sounds appear. We use a Bayesian model to illustrate how feedback from segmented words might constrain phonetic category learning by providing information about which sounds occur together in words. Simulations demonstrate that word-level information can successfully disambiguate overlapping English vowel categories. Learning patterns in the model are shown to parallel human behavior from artificial language learning tasks. These findings point to a central role for the developing lexicon in phonetic category acquisition and provide a framework for incorporating top-down constraints into models of category learning

Teaching Young Remedial Readers to Generate Questions As They Read

Poor readers are often characterized as passive learners who fail to select and apply strategies that will aid their comprehension. Activities designed to develop student use of strategies and self-monitoring may be especially helpful for students who are experiencing reading difficulty in school (Brown, Bransford, Ferrara, and Campione, 1983; Palincsar & Brown, 1984; Pearson & Gallagher, 1983). One activity for enhancing reading comprehension is reciprocal questioning. Teaching students to reflect upon what they have read and to formulate questions about literal and implied meanings of the author can improve comprehension and encourage active monitoring. Previous investigations of reciprocal questioning in different instructional settings and with different populations suggest that this technique is appropriate for remedial readers

Modeling the Learning of the Person Case Constraint

Many domains of linguistic research posit feature bundles as an explanation for various phenomena. Such hypotheses are often evaluated on their simplicity (or parsimony). We take a complementary approach. Specifically, we evaluate different hypotheses about the representation of person features in syntax on the basis of their implications for learning the Person Case Constraint (PCC). The PCC refers to a phenomenon where certain combinations of clitics (pronominal bound morphemes) are disallowed with ditransitive verbs. We compare a simple theory of the PCC, where person features are represented as atomic units, to a feature-based theory of the PCC, where person features are represented as feature bundles. We use Bayesian modeling to compare these theories, using data based on realistic proportions of clitic combinations from child-directed speech. We find that both theories can learn the target grammar given enough data, but that the feature-based theory requires significantly less data, suggesting that developmental trajectories could provide insight into syntactic representations in this domain

Normalization may be ineffective for phonetic category learning

Sound categories often overlap in their acoustics, which can make phonetic learning difficult. Several studies argued that normalizing acoustics relative to context improves category separation (e.g. Dillon et al., 2013). However, recent work shows that normalization is ineffective for learning Japanese vowel length from spontaneous child-directed speech (Hitczenko et al., 2018). We show that this discrepancy arises from differences between spontaneous and controlled lab speech, and that normalization can increase category overlap when there are regularities in which contexts different sounds occur in - a hallmark of spontaneous speech. Therefore, normalization is unlikely to help in real, naturalistic phonetic learning situations

Do Infants Really Learn Phonetic Categories?

Early changes in infants’ ability to perceive native and nonnative speech sound contrasts are typically attributed to their developing knowledge of phonetic categories. We critically examine this hypothesis and argue that there is little direct evidence of category knowledge in infancy. We then propose an alternative account in which infants’ perception changes because they are learning a perceptual space that is appropriate to represent speech, without yet carving up that space into phonetic categories. If correct, this new account has substantial implications for understanding early language development

Modeling Substitution Errors in Spanish Morphology Learning

In early stages of language acquisition, children often make inflectional errors on regular verbs, e.g., Spanish-speaking children produce –a (present-tense 3rd person singular) when other inflections are expected. Most previous models of morphology learning have focused on later stages of learning relating to productionof irregular verbs. We propose a computational model of Spanish inflection learning to examine the earlier stages of learning and present a novel data set of gold-standard inflectional annotations for Spanish verbs. Our model replicatesdata from Spanish-learning children, capturing the acquisition order of different inflections and correctly predicting the substitution errors they make. Analyses show that the learning trajectory can be explained as a result of the gradualacquisition of inflection-meaning associations. Ours is the first computational model to provide an explanation for this acquisition trajectory in Spanish, and represents a theoretical advance more generally in explaining substitution errors in early morphology learning