New Methods of Census Record Linking

The Minnesota Population Center (MPC) has released linked datasets through its NAPP and IPUMS projects, making them readily accessible to researchers. Prior to the availability of complete count census microdata from the MPC, researchers applied various forms of record-linking software. This essay describes the techniques used in the MPC's linking program and briefly compares this technique with those used by other researchers. The key feature of the MPC linking method is the construction of cumulative name similarity scores, based on approximately 2.5 billion record comparisons; we also use support vector mechanics to classify potential links. This article explains modifications made for the final linked datasets and includes a discussion of the role of weighting variables when using linked data.     

Can salmonids (Oncorhynchus spp.) be identified to species using vertebral morphometrics?

Remains of anadromous Pacific salmon and trout (genus Oncorhynchus) are common in archaeological sites from California to Alaska; however, morphological similarity generally precludes species identification, limiting the range of questions that salmonid remains can address in relation to past human use and ongoing efforts in conservation biology. We developed a relatively simple, rapid, and non-destructive way to classify salmon and trout vertebrae from archaeological contexts to species using length, height and the ratio of length to height. Modern reference material was obtained from all seven anadromous Oncorhynchus species native to the west coast of North America. A minimum of ten adult Chinook (Oncorhynchus tshawytscha), chum (Oncorhynchus keta), coho (Oncorhynchus kisutch), pink (Oncorhynchus gorbuscha), and sockeye salmon (Oncorhynchus nerka) and cutthroat (Oncorhynchus clarki clarki) and steelhead trout (Oncorhynchus mykiss) were skeletonized and vertebra length and height were measured. Morphometric analyses compared species classification success based on Linear Discriminant Analysis (LDA), Classification and Regression Trees (CART), and randomForest, with CART performing the best. Classification analyses used all seven species individually, but because of considerable overlap among several species we also conducted analyses on four species groupings. We assigned Chinook salmon and cutthroat to their own groups based on their dissimilarities from each other and the other species. The remaining species were divided into two group complexes (a) chum, coho, and steelhead; and (b) pink and sockeye. When we grouped species according to similar morphology, CART overall success rates increased, ranging from 92 to 100%. Individual species with the highest successful classification rates using CART were Chinook salmon and cutthroat, from 92 to 100%, respectively. We applied our classification to an assemblage of ancient (1000–3000 year old) salmonid vertebrae from the Swiftwater Rockshelters excavations on the upper Wenatchee River in Washington State, U.S.A.     

‘Britishness’, Colonial Governance and Education: St Helenian Children in Colonial Natal in the 1870s

This article considers understandings of ‘Britishness’ in the Natal colony in the 1870s. Focusing on St Helenian children’s expulsion from ‘government’ schools that were ostensibly open to all racial groups, the article shows how competing definitions of race and ‘Britishness’ shaped the responses of colonial officials, settlers and the St Helenian community to the expulsion. The white settler population in Natal was concerned about St Helenian economic migrants’ inclusion in white, English society. In particular, the ambiguous racial status of St Helenians was seen as potentially harmful to white children. The focus on a group of recent incomers to the colony uncovers a process of racialisation unfolding in the context of migrations within the British Empire. The case highlights how movement and migration within the empire could bring these definitions of race and Britishness into conversation and conflict with each other.     

A Two‐Tiered Method for Identifying Trends in Media Framing of Policy Issues: The Case of the War on Terror

Research on media framing of policy issues has flourished. Yet the varied approaches to conceptualizing and operationalizing issue frames that make this literature rich also hinder its advancement. Here, we document the benefits of a two‐tiered method: the first level accounts for issue‐specific frames, while the second level tracks frames that generalize across issues. For this study, we draw on generalizable frames from prospect theory (loss vs. gain frames) and social identity theory (self‐referential vs. other‐referential frames). We discuss the theoretical merits of a two‐tiered approach, arguing that it should yield compound insights greater than the sum of its parts. Applying this method to newspaper coverage of the war on terror, we find a strong trend at the generalizable level: media framing of the war shifted over time from a predominant use of “fear” (self‐referential loss) frames to an increasing use of “charity” (other‐referential gain) frames. Our approach further reveals that the fear frames used in the lead‐up to the Iraq War were not driven by issue‐specific frames related to terrorism or weapons of mass destruction as we might have thought, but rather by frames related to the anticipated threats to U.S. troops. This study sharpens our understanding of how framing of the war evolved, but more broadly it suggests that a two‐tiered approach could be applied both within and across policy issues to advance our understanding of the framing process.