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Hardcover | $45.00 Short | £37.95 | 280 pp. | 6 x 9 in | 19 figures | October 2016 | ISBN: 9780262035323
eBook | $32.00 Short | October 2016 | ISBN: 9780262336369
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The Price of Linguistic Productivity

How Children Learn to Break the Rules of Language


All languages have exceptions alongside overarching rules and regularities. How does a young child tease them apart within just a few years of language acquisition? In this book, drawing an economic analogy, Charles Yang argues that just as the price of goods is determined by the balance between supply and demand, the price of linguistic productivity arises from the quantitative considerations of rules and exceptions. The learner postulates a productive rule only if it results in a more efficient organization of language, with the number of exceptions falling below a critical threshold. 

Supported by a wide range of cases with corpus evidence, Yang’s Tolerance Principle gives a unified account of many long-standing puzzles in linguistics and psychology, including why children effortlessly acquire rules of language that perplex otherwise capable adults. His focus on computational efficiency provides novel insight on how language interacts with the other components of cognition and how the ability for language might have emerged during the course of human evolution.

About the Author

Charles Yang teaches Linguistics and Computer Science and directs the Program in Cognitive Science at the University of Pennsylvania. He is the author of Knowledge and Learning in Natural Language and The Infinite Gift, and is currently writing a book on language change.


“This is the best linguistics book that I have read in a decade. It presents a simple, elegant solution to the problem of reconciling patterns of regularity and irregularity. A compelling property of Yang’s Tolerance Principle is that it works better with small quantities of data, thus providing a novel and insightful answer to those who wonder how children can master a language with so little input. This is a wonderful book and deserves to attract a large audience.”
Mark Aronoff, Distinguished Professor of Linguistics, Stony Brook University; author of Morphology by Itself: Stems and Inflectional Classes
“This excellent book addresses a range of extremely important issues, and brings novel arguments to bear on their resolution. It clarifies the elusive distinction between ‘core’ grammatical facts and the ‘periphery’; makes explicit a standard (though typically vague) approach to how inflectional gaps can be acquired; and presents coherent accounts of some perennial analytic conundrums as the status of various plural marking rules in German. It is the most important work I’ve read in years for the deep basic insights it has to offer on fundamental questions in the theory of grammar.”
Stephen R. Anderson, Dorothy R. Diebold Professor of Linguistics, Yale University; author of Languages: A Very Short Introduction
“Charles Yang’s new book does something that I never thought I would witness in my lifetime; it makes quantitative predictions in a linguistic domain. And by ‘quantitative’ I do not mean giving p-values or confidence intervals or rating scores. I mean numerical predictions about the size of a measurable effect; in fact, many, many measurable effects. That’s quantitative! So run, don’t walk, to your nearest book provider and read the damn thing! It is groundbreaking work.”
Norbert Hornstein, Professor, Departments of Linguistics, University of Maryland
“Charles Yang’s book is full of new insights into enduring questions. For decades our colleagues have debated about rules and exceptions—are there really ‘rules’ in mental representations, or is everything stored as lexical information, exemplars, instances? The Price of Linguistic Productivity provides new data showing that in fact children make a categorical distinction between these two types of representation—and, most important, an insightful computational account of when each will be formed. The Tolerance Principle not only accounts for findings in scores of languages; it also makes new predictions about nonlinguistic concepts—that is, when a generalization will occur in inductive learning, within languages and beyond. This book is a profoundly important contribution to our understanding of language acquisition and of learning.”
Elissa L. Newport, Professor of Neurology, Psychology, and Linguistics, Georgetown University
“Charles Yang proposes a simple rule relating the number of exceptions that a productive rule of grammar can tolerate to the number of regular cases it generates, and provides a diverse set of case studies, including data concerning the course of child language acquisition. The case-studies suggest that it applies with great generality across languages, and across different distributions of regular and irregular forms. His book will be read by linguists, psychologists, cognitive scientists, and all who are concerned with questions of the fundamental nature of human language.”
Mark Steedman, Professor of Cognitive Science, School of Informatics, University of Edinburgh