Factor prices and productivity growth during the British Industrial Revolution

This paper presents new estimates of total factor productivity growth in Britain for the period 1770–1860. We use the dual technique and argue that the estimates we derive from factor prices are of similar quality to quantity-based calculations. Our results provide further evidence, calculated on the basis of an independent set of sources, that productivity growth during the British Industrial Revolution was relatively slow. The Crafts–Harley view of the Industrial Revolution is thus reinforced. Our preferred estimates suggest a modest acceleration after 1800.British industrial revolution, productivity growth, dual measurement of productivity

A rewriting approach to binary decision diagrams

AbstractBinary decision diagrams (BDDs) provide an established technique for propositional formula manipulation. In this paper, we present the basic BDD theory by means of standard rewriting techniques. Since a BDD is a DAG instead of a tree we need a notion of shared rewriting and develop appropriate theory. A rewriting system is presented by which canonical reduced ordered BDDs (ROBDDs) can be obtained and for which uniqueness of ROBDD representation is proved. Next, an alternative rewriting system is presented, suitable for actually computing ROBDDs from formulas. For this rewriting system a layerwise strategy is defined, and it is proved that when replacing the classical apply-algorithm by layerwise rewriting, roughly the same complexity bound is reached as in the classical algorithm. Moreover, a layerwise innermost strategy is defined and it is proved that the full classical algorithm for computing ROBDDs can be replaced by layerwise innermost rewriting without essentially affecting the complexity. Finally a lazy strategy is proposed sometimes performing much better than the traditional algorithm

Developmental pathways linking childhood temperament with antisocial behavior and substance use in adolescence : explanatory mechanisms in the peer environment

This study investigated three developmental pathways involving the peer environment that may explain how certain temperamental dispositions in childhood may become manifested in later antisocial behavior and substance use. A total of 411 (52% boys) Canadian children were followed annually from ages 6 to 15 years. The study tested whether the temperamental traits approach, negative reactivity and attention (assessed at ages 6-7 years), were associated with overt antisocial behavior, covert antisocial behavior and illicit substance use (assessed at ages 14-15 years), via poor social preference among peers, inflated social self-perception and antisocial behavior of peer-group affiliates (assessed throughout ages 8-13 years). Results indicated that negative reactivity was indirectly associated with overt antisocial behavior and substance use via poor social preference. Specifically, negative reactivity in earlier childhood predicted poor social preference in later childhood and early adolescence. This poor social standing among peers, in turn, predicted more engagement in overt antisocial behavior but less substance use in later adolescence. Over and above the influence of social preference, negative reactivity predicted engagement in all three outcomes via children’s antisocial behavior in childhood and early adolescence. Inflated social self-perception and antisocial behavior of peergroup affiliates did not mediate the link between temperament and the outcomes under scrutiny. No sex differences in developmental pathways from temperament to the outcomes were found. To further our understanding of the developmental link between childhood temperament and later antisocial behavior and substance use, we need to recognize the role of peer environmental factors, specifically poor preference among peers

A Bibliometric Analysis of Fragility Fractures: Top 50.

Background and Objectives: The population is aging and fragility fractures are a research topic of steadily growing importance. Therefore, a systematic bibliometric review was performed to identify the 50 most cited articles in the field of fragility fractures analyzing their qualities and characteristics. Materials and Methods: From the Core Collection database in the Thomson Reuters Web of Knowledge, the most influential original articles with reference to fragility fractures were identified in February 2021 using a multistep approach. Year of publication, total number of citations, average number of citations per year since year of publication, affiliation of first and senior author, geographic origin of study population, keywords, and level of evidence were of interest. Results: Articles were published in 26 different journals between 1997 and 2020. The number of total citations per article ranged from 12 to 129 citations. In the majority of publications, orthopedic surgeons and traumatologists (66%) accounted for the first authorship, articles mostly originated from Europe (58%) and the keyword mostly used was "hip fracture". In total, 38% of the articles were therapeutic studies level III followed by prognostic studies level I. Only two therapeutic studies with level I could be identified. Conclusions: This bibliometric review shows the growing interest in fragility fractures and raises awareness that more high quality and interdisciplinary studies are needed

The demographic causes of population change vary across four decades in a long-lived shorebird

Understanding which factors cause populations to decline begins with identifying which parts of the life cycle, and which vital rates, have changed over time. However, in a world where humans are altering the environment both rapidly and in different ways, the demographic causes of decline likely vary over time. Identifying temporal variation in demographic causes of decline is crucial to assure that conservation actions target current and not past threats. However, this has rarely been studied as it requires long time series. Here we investigate how the demography of a long-lived shorebird (the Eurasian Oystercatcher Haematopus ostralegus) has changed in the past four decades, resulting in a shift from stable dynamics to strong declines (−9% per year), and recently back to a modest decline. Since individuals of this species are likely to respond differently to environmental change, we captured individual heterogeneity through three state variables: age, breeding status, and lay date (using integral projection models). Timing of egg-laying explained significant levels of variation in reproduction, with a parabolic relationship of maximal productivity near the average lay date. Reproduction explained most variation in population growth rates, largely due to poor nest success and hatchling survival. However, the demographic causes of decline have also been in flux over the last three decades: hatchling survival was low in the 2000s but improved in the 2010s, while adult survival declined in the 2000s and remains low today. Overall, the joint action of several key demographic variables explain the decline of the oystercatcher, and improvements in a single vital rate cannot halt the decline. Conservations actions will thus need to address threats occurring at different stages of the oystercatcher's life cycle. The dynamic nature of the threat landscape is further supported by the finding that the average individual no longer has the highest performance in the population, and emphasizes how individual heterogeneity in vital rates can play an important role in modulating population growth rates. Our results indicate that understanding population decline in the current era requires disentangling demographic mechanisms, individual variability, and their changes over time

Disturbance increases high tide travel distance of a roosting shorebird but only marginally affects daily energy expenditure

Background: Anthropogenic disturbance can negatively affect an animal's energy budget by evoking movement responses. Existing research focuses mainly on immediate displacement as a disturbance effect, since this can be easily observed in the field. However, effects on movement over longer timescales are poorly examined and it is largely unknown if and to what extent they reflect immediate responses. Longer-term responses could for example be larger than immediate responses if birds, after disturbance, return to the original location and thereby travel twice the immediate disturbed distance. Methods: We combined GPS tracking data with observational data to quantify the effects of anthropogenic (air force and walkers) and non-anthropogenic disturbances on distances travelled by roosting Eurasian Oystercatchers (Haematopus ostralegus) during the non-breeding season. We compared immediate displacement after a disturbance with distance travelled during the entire high tide period (longer-term response), while accounting for environmental factors. Additionally, we calculated energy expenditure due to disturbance based on observed disturbance frequencies. Results: Disturbance resulted in an immediate displacement response of ~ 200 m (median). Air force disturbances tended to yield larger immediate responses than walker and, especially, than non-anthropogenic disturbances. Longer-term responses and immediate responses were approximately similar, suggesting that, over longer timescales, spatial disturbance effects in the study area remain confined to immediate effects. However, disturbances were infrequent (0.17 disturbances per bird per hour) and most disturbances were of natural origin (62%). Consequently, anthropogenic disturbance of roosting oystercatchers in the study area on average costs 0.08% of the daily energy expenditure. Conclusions: Our results suggest that immediate spatial responses to disturbance can be a useful proxy for spatial responses over longer timescales. Over the non-exhaustive range of conditions investigated, energetic consequences of spatial disturbance responses for an oystercatcher in the study area are marginal due to low disturbance levels

State-dependent environmental sensitivity of reproductive success and survival in a shorebird

To understand the consequences of anthropogenic and environmental changes for wildlife populations, it is important to study how individuals differ in their sensitivity to environmental change, and whether this depends on individual characteristics. An individual’s reproductive performance may provide an integrative, unidimensional proxy of an individual’s characteristics. In this study, we define an individual’s characteristics by three such reproductive states, namely successful-, failed-, and non-breeders in the previous year. We used a 16-year dataset of individually marked breeding Eurasian Oystercatchers Haematopus ostralegus to examine the inter-annual fluctuations in reproductive success and survival among breeding states, and their state-dependent sensitivity to environmental conditions. Environmental conditions included available biomass of the main prey species of breeding Oystercatchers (Ragworm, Baltic Tellin and Lugworm), tidal height which reflects one of the main causes of nest loss (flooding) and conditions that may impact the energetic requirements during incubation, such as temperature. We also included environmental variables measured in winter, including available biomass of the main winter prey species (Blue Mussel and Common Cockle) along with factors that may affect food availability and energetic requirements for homeostasis, namely bivalve weight loss, windchill, winter severity, and precipitation. Breeding birds that were successful the previous year had higher survival, and were more likely to remain successful, than failed- and non-breeders. The effects of environmental conditions acted in the same direction on reproductive success but had opposite effects on survival among the three breeding states, especially for windchill and Blue Mussel biomass. The contrasting state-dependent effects of the environment on survival thus averaged out when examining consequences for lifetime reproductive nest success (LRnS); instead LRnS was largely influenced by environmental conditions acting upon reproduction. Our study indicates that an individual’s previous breeding state provides an integrative measure of heterogeneity in individuals’ sensitivity of reproduction and survival to environmental change. Incorporating previous breeding state as a source of individual heterogeneity in population modelling may improve predictions of future population dynamics in a rapidly changing world