Rebecca Lenihan's From Alba to Aotearoa is a valuable contribution to studies of the Scottish diaspora in Australasia. Its value derives from Lenihan's method as much as her content and findings. Through rigorous statistical analysis, Lenihan has established a detailed demographic profile of Scottish migrants who arrived in New Zealand between 1840 and 1920. Lenihan asks and answers a number of core questions of her extensive data: From where in Scotland did migrants to New Zealand come? Who came, when, and in what numbers? Where in New Zealand did they settle? Lenihan also explores return migration from New Zealand, internal migration within Scotland (often the first step of longer journeys), and occupational mobility.

This is important work. In Australia and New Zealand, precise demographic analysis and profiling of migrants and their descendants has either been overlooked or, more commonly, impossible due to a lack of appropriate data. In Australia, immigration and shipping records are often opaque at best, and historic census data for individuals has been destroyed. Lenihan notes that historians of migration to New Zealand have been similarly frustrated by the nonexistence or limited availability of original census records, shipping records, and official emigration records. Instead, Lenihan's bases for this book are two extensive datasets: the New Zealand Society of Genealogists Scottish Interest Group's Register of New Zealand Immigrants of Scottish Birth Arriving Before 1 January 1921; and data from the New Zealand Ministry of Culture and Heritage's People of New Zealand project. These datasets contain information for thousands of individuals regarding origins, parentage, arrival, settlement, occupation, marriage, age, and children, and they allow Lenihan to carefully trace migrants from Scotland to New Zealand and across a number of generations.

Drawing on these two datasets, Lenihan sets out to provide quantitative background to the many social and cultural histories of Scots in New Zealand that have appeared in recent years, often focusing on migrant networks, cultural practices, and identities. The study both confirms and challenges stereotypes about New Zealand's Scots. Scottish migration to New Zealand, for example, was not dominated by Highlanders. Indeed, in the period under study, migrants represented an almost exact geographical cross-section of Scotland. Neither were they forced to emigrate or “cleared.” Most nineteenth-century Scottish migrants made the decision to leave their homes within the context of vast economic transformations at home, to be sure, but they almost always left willingly. Furthermore, migrants from Scotland settled in high concentrations across many parts of New Zealand, not just in commonly cited areas, such as Otago. While much has been made of migrant networks, Lenihan finds that chain and cluster migration to New Zealand was relatively uncommon in comparison to other destinations for Scottish migrations; the exception were those migrants from Shetland. As is well accepted, Scots were significantly overrepresented in New Zealand. They made up around 10 percent of the population of the British Isles, yet contributed to 24 percent of New Zealand's immigration.

Lenihan's study demonstrates the value of existing genealogical research to historians, who can combine these extensive, but often ignored, datasets with new, powerful digital technologies and statistical analysis software (indeed, the appendices provide useful insight into the processes and problems of this work). The quantitative analysis contained within this study is rigorous, and it represents the kind of scholarship that has, by and large, fallen out of favor with historians since the “cultural turn” took hold. Scholars who have become used to cultural history may find themselves losing the forest for the trees, so to speak. Yet this kind of research provides an essential demographic baseline for challenging and complicating the nearly exhausted themes of culture and identity among Scotland's migrants. Perhaps more importantly, the provision of this statistical background helps to uncover the frequently overlooked diversity of the Scottish diaspora. It is, indeed, often the case that “Scottish diaspora” is far too capacious to make sense as a category for analysis; demographic precision can help to provide finer detail of the thousands of individuals grouped together, often haphazardly and retroactively, as a “diaspora.”

In many cases, Lenihan confirms previous suspicions or restates existing conclusions from her previous research in, for instance, her co-authored book, Unpacking the Kists: The Scots in New Zealand (2013). The analyses do, however, provide persuasive contrary evidence to the continued insistence that Scottish migrants were, for the most part, tartan-clad Highlanders forced by English and Lowland agriculturalists to leave their homes and communities. In settler colonial societies, such as New Zealand, the reimagining of “Celtic” colonists as victims on par with indigenous populations continues apace, yet this book is perhaps too scholarly to provide a popular corrective. Lenihan's study does, however, demonstrate how historians can utilize extensive data and careful methodology to present a finer-grained picture of the experiences of migrants so often spoken of in abstraction and generalization.