What Can Causal Process Tracing Offer to Policy Studies? A Review of the Literature

Causal process tracing (CPT) has emerged as an important method of causal inference in qualitative social science research, most notably in case study research designs. There is now a considerable literature on the aims, philosophical groundings, and methods of process tracing. This paper reviews the CPT literature to assess what new directions it may suggest for policy studies. The first part of the paper sets out the methodological advantages CPT offers in building and testing theories of policy change, most notably in supporting a theoretical pluralism to address the problem of complexity in policy studies. Building on recent scholarship across the social sciences, the second part examines step by step the recently minted “best practice” for undertaking CPT in policy studies. This part includes discussion of the possible pitfalls of CPT as a method; common errors involved in its use are set out and minimization strategies offered. In particular, while acknowledging the usefulness of Bayesian tests for causality as heuristic devices, we emphasize the limitations of applying such tests in practice. Possible correctives are suggested. The final part of the paper speculates more generally on the potential of CPT to improve our investigation of patterns of policy change over time.     

Coarse cloth and clerical tailoring: negotiating Boston-Irish cultural imperatives in the Famine era

Recent calls for updated approaches to the Irish-American historical experience recommend more systematic attention to complexities inherent in Irish immigration and settlement. They also seek further contextualisation of the history of the Irish in the USA within broader North American, transatlantic and global frameworks. The need to review and potentially reappraise longstanding, essentialist perspectives on Irish arrival and assimilation is equally evident. This article expands on foundational narrative histories of the Boston Irish to re-examine Famine-era settlement and contending agendas within spheres of religious affiliation and political activism. The character and evolution of Irish-American ethnic identity, and the tragic imprint of the Famine under consideration here pave the way for new readings of traditional orthodoxies. Collectively, they reveal Boston's Irish historical terrain to be more complex than the record currently suggests.     

Strontium and stable isotope evidence for diet and mobility in Roman Gloucester,UK

This paper presents the results of a multi-isotopic (oxygen, strontium, carbon and nitrogen isotopes) investigation of population and dietary diversity in Roman Gloucester, focusing on individuals found in a late 2nd century AD mass burial pit at London Road, and comparing them to those found in the nearby cemetery. There were no statistical differences in isotopic composition between mass grave and cemetery burials, suggesting, in agreement with the osteological evidence, that the mass burial was the result of a catastrophic event, probably an epidemic disease. Strontium and oxygen isotope analysis demonstrated considerable diversity in the origins of the Gloucester population, with evidence for both UK and non-UK individuals. Diet was predominately terrestrial and similar to that of other Romano-British populations. Elevated δ¹³C_dentine ratios in some individuals are correlated with raised δ¹⁸O_p values and are therefore probably due to childhoods spent in warmer climates, rather than dietary variation.     

Zooarchaeological perspectives on the Chinese Early and Late Paleolithic from the Ma’anshan site (Guizhou,South China)

Ma’anshan is a Paleolithic cave site in the Guizhou province of southern China. The total area of the excavations is ca. 48 m², and the cultural deposit is divided into two layers representing the Chinese Late Paleolithic and the later part of the Early Paleolithic. The upper layer dates between 19,295  BP and 31,155 BP by AMS technique, and the lower layer is dated to around 53,000 BP by U-Series technique. Thousands of bone fragments were recovered from the two layers. Species abundance, bone surface modifications, skeletal element representation, and mortality patterns were studied in an investigation of assemblage formation history and patterns of prey selection and meat consumption by hominins. Interpretations of the faunal data are strengthened by reference to experimental studies and ethnoarchaeological data. The zooarchaeological data indicate that the later occupants of Ma’anshan Cave hunted mainly medium and small game animals, while the earlier occupants tended to prey upon larger animals. In the later period, hominins also made fuller use of the carcasses. The breadth of the meat diet increased with time, due to the inclusion of quick small animals (bamboo rats and birds) in the later period. The differences between the two faunal assemblages are consistent with the chronologic boundary currently drawn between the Chinese Early and Late Paleolithic ca. 30–27 ka BP, based on technological and other evidence.     

Poaceae phytoliths from the Niassa Rift,Mozambique

The most common grass phytoliths from “Zambezian” miombos are described here for the first time. Their potential for long term preservation in sediments makes them a useful tool in the reconstruction of ancient plant communities and plant/human interactions. We processed 60 plant samples (26 identified genera and species), with an average of 300 phytoliths counted per sample to a total of 18,586. Forty-seven morphotypes were described as per the International Code for Phytolith Nomenclature, with exceptions, including forty-five discreet shapes and two articulated forms, which can be used as comparative reference materials. We conducted three forms of statistical analyses: Discriminant Analysis, Cluster Analysis, and Principal Component Analysis. The highest biomineral content was recorded among the Bambuseae and Paniceae, while the lowest silica production is detected in the Cynodonteae tribe. Typologically, the subfamily Panicoideae yielded 50% of the types reported here, 32% are from the Chloridoideae, 12% from the Bambusoideae, and 8% from the Arundinoideae sensu lato. Overall, the idealized Zambezian Poaceae phytolith spectrum is dominated by a small subset of Poaceae short cells, which include five morphotypes conventionally associated with Panicoid grasses (Bilobate concave outer margin long shaft, Bilobate concave outer margin short shaft, Bilobate convex outer margin long shaft, Bilobate convex outer margin short shaft, Cross), one morphotype commonly seen in Chloridoid taxa (saddle), and two types that appear across subfamily boundaries (tower, tower horned). The next logical step to take in regional phytolith research is the account of phytoliths deposited in soils underneath living plants, for they represent the interface between existing vegetation communities and the inevitably distorted fossil assemblages that the paleobotanist uses for environmental reconstruction.     

Use-wear analysis of an Amudian laminar assemblage from the Acheuleo-Yabrudian of Qesem Cave,Israel

In this paper the results of use-wear analysis of an Amudian lithic assemblage recently discovered at Qesem Cave, Israel, are presented. Although very old, this assemblage maintains well-preserved traces of use that indicate that butchering activities and plants collecting were carried out at the site. Cut marks on faunal remains confirm the observations obtained by use-wear analysis.