One of the most striking findings of the Atlas of North American English (Labov, Ash & Boberg Reference Labov, Ash and Boberg2006:10, 304) was that regional dialects of English in North America continue to diverge, at least on some levels, despite the popular assumption that dialect differences must be disappearing in an age of general education, high mobility, and instant electronic communication. To be sure, there were also some clear cases of convergence, but a rapid and general loss of regional distinctiveness was not found. On the contrary, in some cases change appeared to be driving neighboring dialects in opposite directions. Today, the struggle between forces of convergence and divergence is a central theme of the story of language change, as it always has been; from a comparative perspective, any change in a language or dialect causes either divergence from or convergence with neighboring varieties. These processes account for both the diversification of language families and the loss of diversity. Convergence now demands the greater share of most people's attention, as external developments in the modern world have undoubtedly amplified the pressures favoring convergence and diminished the possibilities for divergence. Indeed, these developments are of interest not just to dialectologists, but also to linguists and cultural historians generally, since the same pressures that lead to the loss of dialects can lead to the loss of entire languages and to some extent the cultures to which they give expression. A book examining these processes in the languages of Europe – a region particularly susceptible to the forces favoring convergence – is therefore a timely and welcome addition to linguistic scholarship.

Auer, Hinskens & Kerswill have edited a strong collection of papers that discuss convergence and/or divergence in a wide range of languages, especially Belarussian, Danish, Dutch, English, German, Italian, and Spanish. The essays are divided into three sections, following an introductory chapter by the editors. Part 1, dealing with convergence, divergence, and linguistic structure, has chapters by Jeffrey Kallen on /t/-lenition in Irish English, by Gaetano Berruto on the different types of dialect contact in Italy, by Leonie Cornips & Karen Corrigan on syntactic change in Limburg Dutch, and by Jenny Cheshire, Paul Kerswill & Ann Williams on dialect change at different levels of grammar in three English towns. Part 2, dealing with macro-sociolinguistic motivations of convergence and divergence, contains chapters by Inge Lise Pedersen on standardization in Scandinavia, by Paul Kerswill & Peter Trudgill on the formation of new dialects, by Peter Rosenberg on the development of German in speech islands in the former Soviet Union, by Curt Woolhiser on the divergence of Belarussian dialects on either side of the Polish border, and by Johan Taeldeman on the spatial diffusion of features of Belgian Dutch. Part 3, dealing with micro-sociolinguistic motivations, comprises essays by Tore Kristiansen & Jens Normann Jørgensen on the loss of traditional dialects in Denmark, by Juan Andres Villena-Ponsoda on the effect of social networks on Spanish in Málaga, and by Peter Auer & Frans Hinskens on the role of interpersonal accommodation in language change.

Readers expecting a simple account of widespread dialect convergence in a Europe overwhelmed by forces of modernization and globalization will be surprised by the complexity of the situation presented by the editors in their introductory essay. Not only are forces of convergence balanced by forces of divergence, as Labov, Ash & Boberg find in North America, but these forces interact with other factors such as standard languages and political boundaries. In fact, there is so much detail in the picture the editors present that it is difficult to discern any general principles or an overarching trend. At a few points (e.g., 23–24, 35), they do discuss the major, long-term economic, social, and cultural changes that most casual observers would point to as likely agents of convergence – particularly the transition of the majority of the European population from small, isolated, agriculture-based communities to large, cosmopolitan, industrial cities, but also the transition from large, extended family structures to nuclear families in which the conservative influence of older generations on language development is reduced (32). To these factors might be added the rising prevalence of non-parental, institutional care for very young children and even infants, alluded to in the Danish context by Pedersen (190): The replacement of mothers by a succession of state or commercial employees as the primary influence on the early linguistic development of children presumably has considerable effects on the stability and intergenerational transmission of traditional speech varieties (among other things), though what these effects are probably depends on local conditions in each case. However, there is no suggestion that any of these changes is producing an overwhelming pattern of convergence. On the contrary, the editors refer to a counter-development, in reaction to forces of globalization, that may be producing a resurgence of local dialects in some places (36).

In the face of this complexity, the editors helpfully propose an agenda of ten general research themes for the study of dialect change: internal factors (the role of structural forces in contact and of formal linguistic theory in understanding contact); isolation and contact; the role of the standard variety; the role of social and physical geography; the role of demographic and sociopolitical processes; the role of social networks and other “mesosocial” structures; the role of social-psychological factors such as identity and attitudes; the interaction of internal, external, and extralinguistic factors; the salience of the features involved in change; and comprehensive models of the outcomes of convergence and divergence. Unfortunately, the editors' own effort at the last of these goals is less than satisfying. They develop a “probabilistic model” of outcomes of dialect change (convergence vs. divergence), based on several factors: whether the change is internal or external in origin (e.g., sound change vs. borrowing), what kind of innovation is involved, and whether one or both systems are innovating (42). However, it turns out that in three of the six cases the model cannot decide between convergence and divergence. It makes a clear prediction in only half the cases. In the end, what this prediction amounts to is that in cases of externally derived change, such as borrowing or other contact effects, we should find convergence, while in spontaneous, internally derived change, such as sound change, we should find divergence. This rather obvious conclusion hardly merits a formal model; that contact between languages leads to convergence while spontaneous change in isolation from other varieties leads to divergence is a basic lesson of introductory dialectology and hardly a new proposal. Nevertheless, the editors' review of the theoretical and methodological issues in the field is both comprehensive and insightful. North American readers in particular may be impressed by the quantity and diversity of British and European research on variation and change, much of it unfamiliar, addressing themes that are also of interest, if in somewhat modified contexts, in North America.

The Atlantic divide in dialect studies is emphasized in another way by a few small errors of fact that will be detectable to someone who works more closely on North American English than do any of the editors. In their discussion of the raising of /æ/ (19), the editors characterize raised variants as “identical” to the dress and face vowels, which is inaccurate: They have in-glides that make them clearly distinguishable from these vowels. Moreover, /r/ is not among the environments that condition raising in Philadelphia or anywhere else, as suggested here: The merger of /æ/ and /e/ before /r/ (marry and merry) is an independent phenomenon with a completely different spatial distribution. Further on, in a discussion of the role of political borders, Canadian Raising is chosen to exemplify features delimited by a border (29). This is a bad choice, as Canadian Raising, despite its name and its alignment in some places with the southern border of Canada, is neither found consistently within nor excluded consistently outside Canada's borders, being found in several locations in the United States, most famously on Martha's Vineyard. However, these are minor flaws in an otherwise careful and well-informed presentation.

The editors state that the aim of their volume is to examine sociolinguistic and dialect-geographical phenomena from a perspective informed by linguistic theory, and thereby to proceed from descriptions of particular cases to the development of a general theory of dialect divergence and convergence (48). Whether or not this ultimate goal will eventually be achieved, the chapters that follow the introduction certainly exemplify a wide range of theoretical approaches and a sincere effort to narrow the intellectual gulf between dialectology and general linguistics, as has long been advocated by William Labov, among others. For instance, Kallen's paper provides tableaux showing how the various outcomes of /t/ lenition can be understood in terms of different constraint rankings in an Optimality Theory framework, while Cornips & Corrigan analyze the evolution of middle constructions in Dutch in the Principles and Parameters approach of generative syntax. There are theoretical connections with other fields, too, emphasizing the interdisciplinary nature of dialect study; for example, Villena's analysis of social networks is linked with sociology, Kristiansen & Jørgensen's analysis of attitudinal factors in Danish dialect convergence with social psychology, and Taeldeman's critical evaluation of diffusion models with geography. The last contribution was particularly interesting to this reviewer, as it identified the same limitations to the gravity model of linguistic diffusion that he found to operate at the U.S./Canada border: Attitudinal (social-psychological) and structural (linguistic) factors often subvert the predictions of a model based exclusively on distance and community size (Boberg Reference Boberg2000).

The 14 chapters in this volume present a vast array of data and an intriguing range of analyses to readers interested in the rise and fall of dialect variation. Scholars not familiar with the breadth or depth of this work in Europe will find here a stimulating introduction to the subject. The book would make an excellent text for a graduate seminar; the integrated index and list of references at the end increase its usefulness for students and scholars alike. While there is no simple answer to the question of whether Europe's dialects are vanishing, this book contains a remarkable amount of knowledge that could inform a wide diversity of compelling views.