116 research outputs found

    The vector innovation structural time series framework: a simple approach to multivariate forecasting

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    The vector innovation structural time series framework is proposed as a way of modelling a set of related time series. Like all multi-series approaches, the aim is to exploit potential inter-series dependencies to improve the fit and forecasts. A key feature of the framework is that the series are decomposed into common components such as trend and seasonal effects. Equations that describe the evolution of these components through time are used as the sole way of representing the inter-temporal dependencies. The approach is illustrated on a bivariate data set comprising Australian exchange rates of the UK pound and US dollar. Its forecasting capacity is compared to other common single- and multi-series approaches in an experiment using time series from a large macroeconomic database.Vector innovation structural time series, state space model, multivariate time series, exponential smoothing, forecast comparison, vector autoregression.

    Cultural mosaics, social structure, and identity: The Acheulean threshold in Europe

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    The period between 600 and 400 ka is a critical phase for human evolution in Europe. The south and northwest saw a dramatic increase in sites, the spread of handaxe technology alongside bone and wooden tool manufacture, efficient hunting techniques, and the use of fire. Lithic assemblages show considerable variation, including the presence/absence of handaxes and tool morphology. To explain this variation, we propose the Cultural Mosaic Model, which suggests that there is a range of expressions of the Acheulean, with local resources being instrumental in creating distinct material cultures with or without handaxes. We argue that if typologically and technologically distinct assemblage types are regionally distributed, chronologically separated, and persistent over time, then they are unlikely to be caused purely by raw material constraints or functional variation but rather reflect populations with different material cultures. We initially assess the model using British data. Britain was a northwestern peninsula of Europe, and oscillations in climate led to episodic occupation. The terraces of the pre-MIS 12 Bytham River provide a framework for dating occupation to MIS 13 and 15, while during MIS 11, archaeological sites with rich environmental records can be dated to substage level. We suggest there are six chronologically and typologically distinct assemblage types that reflect a series of population incursions into Britain. We review the broader European lithic record, which is consistent with the Cultural Mosaic Model. In developing the model, we suggest that during stable climate, localized cultures developed, while climatic change led to shifts in population, with increased knowledge exchange and gene flow. We suggest that group expression through material culture was an important stage in social development by promoting group cohesion, larger group size, better cooperation, improved knowledge transfer, and enabling populations to survive in larger foraging territories in northern Europe

    Palaeolithic archaeology of the Bytham River: human occupation of Britain during the early Middle Pleistocene and its European context

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    The Early and early Middle Pleistocene archaeological record in Britain from c. 900 to 500 ka marks a critical shift in human occupation of northwest Europe, from occasional pioneer populations with simple core and flake technology to more widespread occupation associated with the appearance of Acheulean technology. Key to understanding this record are the fluvial deposits of the extinct Bytham River in central East Anglia, where a series of Lower Palaeolithic sites lie on a 15 km stretch of the former river. In this paper we present the results of new fieldwork and a reanalysis of historical artefact collections of handaxes and scrapers to: 1) establish the chronostratigraphic context of the Bytham archaeological record; 2) examine variability in lithic artefact typology and technology through time; and 3) explore the implications for understanding variation in lithic technology in the European record. Six phases of occupation of Britain are identified from at least marine isotope stage (MIS) 21 to MIS 13, with the last three phases characterised by distinctive lithic technology. We argue that this relates to the discontinuous occupation of Britain, where each phase represents the arrival of new groups derived from different European populations with distinctive material culture

    Making a U-turn on the Purfleet Interchange: Stone Tool Technology in Marine Isotope Stage 9 Britain and the Emergence of the Middle Palaeolithic in Europe

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    This paper re-examines earlier Palaeolithic core technology from British sites assigned to MIS 11, 9, and 7 using primarily a châine opératoire approach, with the objective of better understanding the earliest occurrence and distribution of Levallois and other prepared-core technologies across the Old World. Contrary to previous interpretations (White and Ashton in Current Anthropology, 44: 598–609, 2003), we find no evidence for a true Levallois concept in MIS 11 or MIS 9 in Britain. Cores previously described as ‘simple prepared cores’ or ‘proto-Levallois’ cores show neither evidence of core management nor predetermination of the resulting flakes. They can instead be explained as the coincidental result of a simpler technological scheme aimed at exploiting the largest surface area of a core, thereby maximising the size of the flakes produced from it. This may be a more widespread practice, or a local solution derived from existing principles. Levallois appears fully formed in Britain during terminal MIS 8/initial MIS 7. Consequently, Britain does not provide evidence for an in situ evolution of Levallois, rather we argue it was introduced by new settlers after a glacial abandonment: the solution to the emergence and significance of Levallois lies in southern Europe, the Levant and Africa

    Making a U-turn on the Purfleet Interchange: Stone Tool Technology in Marine Isotope Stage 9 Britain and the Emergence of the Middle Palaeolithic in Europe

    Get PDF
    This paper re-examines earlier Palaeolithic core technology from British sites assigned to MIS 11, 9, and 7 using primarily a châine opératoire approach, with the objective of better understanding the earliest occurrence and distribution of Levallois and other prepared-core technologies across the Old World. Contrary to previous interpretations (White and Ashton in Current Anthropology, 44: 598–609, 2003), we find no evidence for a true Levallois concept in MIS 11 or MIS 9 in Britain. Cores previously described as ‘simple prepared cores’ or ‘proto-Levallois’ cores show neither evidence of core management nor predetermination of the resulting flakes. They can instead be explained as the coincidental result of a simpler technological scheme aimed at exploiting the largest surface area of a core, thereby maximising the size of the flakes produced from it. This may be a more widespread practice, or a local solution derived from existing principles. Levallois appears fully formed in Britain during terminal MIS 8/initial MIS 7. Consequently, Britain does not provide evidence for an in situ evolution of Levallois, rather we argue it was introduced by new settlers after a glacial abandonment: the solution to the emergence and significance of Levallois lies in southern Europe, the Levant and Africa
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