Diverging Trends in Aggregate and Firm-Level Volatility in the UK

This paper documents an increase in the volatility of output at the firm level in the United Kingdom, in keeping with recent research for the United States. Evidence at the sectoral level suggests that this may have arisen as a result of increased product market competition. This greater volatility at the firm level has also occurred at a time of greater macroeconomic stability, commonly referred to as the ‘Great Stability’. National accounts data for 31 sectors in the economy show that the fall in aggregate volatility is mostly a result of lower covariance between sectors rather than individual sectors becoming less volatile. This suggests a possible role for structural change in explaining the causes of the ‘Great Stability’.

Ascape: Abstracting complexity

Software tools used in science typically take a kitchen-sink approach to design. From statistics to mathematics to engineering to agent modeling, even those tools that have a strong organizing theme tend towards supporting every contingency and methodology. This impulse toward generalization and breadth is laudable and necessary. However, there is a complementary case to be made for the discipline of abstraction, parsimony, and depth, and that is the case I make for Ascape. I argue in general for the importance of abstraction in agent-based modeling. I then discuss three key abstractions enforced in Ascape, and the opportunities they create for expressibility and simplicity. While these abstractions seem especially suited to the domain of social and economic systems, they are not limited to it. By drawing concrete examples from Ascape and comparing Ascape code to other environments, I show how these apparently constraining abstractions benefit the Ascape user and developer experince. In summary, a primary goal of software design and coding is conquering complexity. The motivation behind many programming practices is to reduce a program\u27s complexity. Reducing complexity is a key to being an effective programmer. -Steve McConnell (1993

Media consumption and creation in attitudes toward and knowledge of inflammatory bowel disease: web-based survey

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic gastrointestinal condition affecting over 5 million people globally and 1.6 million in the United States but currently lacks a precisely determined cause or cure. The range of symptoms IBD patients experience are often debilitating, and the societal stigmas associated with some such symptoms can further degrade their quality of life. Better understanding the nature of this public reproach then is a critical component for improving awareness campaigns and, ultimately, the experiences of IBD patients. OBJECTIVE: The objective of this study was to explore and assess the public's awareness and knowledge of IBD, as well as what relationship, if any, exists between the social stigma surrounding IBD, knowledge of the disease, and various media usage, including social media. METHODS: Utilizing a Web-based opt-in platform, we surveyed a nationally representative sample (n=1200) with demographics mirroring those of the US Census figures across baseline parameters. Using constructed indices based on factor analysis, we were able to build reliable measures of personal characteristics, media behaviors, and perceptions and knowledge of IBD. RESULTS: Among the American public, IBD is the most stigmatized of seven diseases, including genital herpes and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Additionally, IBD knowledge is generally low with 11.08% (133/1200) of the sample indicating no familiarity with the disease and 85.50% (1026/1200) of participants inaccurately answering two-thirds of the IBD index questions with which their knowledge was assessed. Increased knowledge of IBD is associated with lower levels of stigma. However, social media use is currently related to lower levels of IBD knowledge (P<.05). Furthermore, findings indicate that participants who most frequently engaged in producing social media content are less knowledgeable about IBD (P<.10), highlighting the potential for a dangerous cycle should they be contributing to a Web-based IBD dialogue. CONCLUSIONS: Greater efforts must be taken to stymie IBD misinformation across all media, but especially in social media channels, to increase IBD knowledge and reduce stigma surrounding IBD. These findings pave the way for further research qualitatively examining the pervasiveness of specific IBD messages found in today's social media landscape and their impact on enacted stigmas so as to better equip providers and patient advocacy organizations with impactful communication solutions

Margaret Chase Smith Essay: High School Student Essay Winners

Maine has benefited from the public service of many well-respected and influential national leaders over the last two centuries. One of them, Senator Margaret Chase Smith, offered her reflections on leadership at a time when the United States faced a struggle for civil rights at home and the tensions of the Cold War abroad. With the country currently confronting challenges such as the threat of terrorism, ongoing tensions in the Middle East, and the taint of corporate scandals, the Margaret Chase Smith Library annual essay contest invited Maine high school seniors to reflect on the qualities leaders will need to possess in order to be more effective in the twenty-first century. We feature here the three top prize-winning essays by Emily Parker (first), Rachel Culley (second) and Miles Kirby (third)

Inflation Dynamics

This thesis studies inflation dynamics, investigating both reasons why prices change, and why they sometimes do not. It investigates four areas that are of interest to monetary policy makers, but where our knowledge is incomplete. The first area investigated is the causes of price stickiness at the firm level. Insight is given by a large survey of price-setting behaviour of New Zealand firms. There is a large degree of heterogeneity in price-setting practices between, and within, sectors. Explicit contracts, implicit contracts and strategic complementarity are the most widely recognised causes of price rigidity. Menu costs and sticky information are not widely recognised. The second area investigated is how exporters price, and in particular the decisions over currency of invoice and whether to differentiate prices across markets. In sharp contrast to commonly held views, we find that primary sector firms do differentiate prices across markets. Indeed, these firms are more likely to do so in New Zealand than firms in other sectors. Larger, and more productive firms, are more likely to differentiate prices. This thesis then studies the influence that global inflation factors have on domestic inflation. A CPI database for 223 countries and territories extends the previous research, which focuses on high income countries. Global factors explain a large share of the variance of national inflation rates in advanced countries, but not for less developed countries. More generally, global factors have greater influence in countries with higher GDP per capita, financial development and central bank transparency. Global factors explain a large share of the variance of food and energy prices but a much smaller share of the variance of other sub-components. Finally, this thesis carries out the first systematic analysis of the impact on inflation of disasters caused by natural hazards. There is a large degree of heterogeneity, with disasters having little significant effect in advanced countries, but having effects that can persist for years in developing economies. There are also differences between types of disasters and sub-indices of inflation. Storms have a short-run impact on food price inflation that lasts for the first two quarters, before being reversed in the subsequent two. Earthquakes reduce CPI inflation excluding food, housing and energy

An Agent-Based Model of Signal Transduction in Bacterial Chemotaxis

We report the application of agent-based modeling to examine the signal transduction network and receptor arrays for chemotaxis in Escherichia coli, which are responsible for regulating swimming behavior in response to environmental stimuli. Agent-based modeling is a stochastic and bottom-up approach, where individual components of the modeled system are explicitly represented, and bulk properties emerge from their movement and interactions. We present the Chemoscape model: a collection of agents representing both fixed membrane-embedded and mobile cytoplasmic proteins, each governed by a set of rules representing knowledge or hypotheses about their function. When the agents were placed in a simulated cellular space and then allowed to move and interact stochastically, the model exhibited many properties similar to the biological system including adaptation, high signal gain, and wide dynamic range. We found the agent based modeling approach to be both powerful and intuitive for testing hypotheses about biological properties such as self-assembly, the non-linear dynamics that occur through cooperative protein interactions, and non-uniform distributions of proteins in the cell. We applied the model to explore the role of receptor type, geometry and cooperativity in the signal gain and dynamic range of the chemotactic response to environmental stimuli. The model provided substantial qualitative evidence that the dynamic range of chemotactic response can be traced to both the heterogeneity of receptor types present, and the modulation of their cooperativity by their methylation state

Beyond ‘peer pressure’: rethinking drug use and ‘youth culture’

The study of drug use by young people in the West has been transformed over the last decade by the development of sociological approaches to drug use which take serious account of the cultural context in which young people encounter drugs. One consequence is that the notion of ‘peer pressure’, as the primary articulation of the engagement between youth culture and drug use, has been displaced by that of ‘normalisation’, which envisages ‘recreational’ drug use as one expression of consumer-based youth cultural lifestyles. In stark contrast, academic discussion of drug use in Russia remains primarily concerned with the prevalence and health consequences of (intravenous) drug use while explanations of rising rates of drug use focus on structural factors related to the expansion of drugs supply and, to a lesser extent, post-Soviet social and economic dislocation. In this article, original empirical research in Russia is used to develop an understanding of young people's drug use that synthesises structural and cultural explanations of it. It does this by situating young people's narratives of their drugs choices in the context of local drugs markets and broader socio-economic processes. However, it attempts to go beyond seeing structural location as simply a ‘constraint’ on individual choice by adopting an understanding of ‘youth culture’ as a range of youth cultural practices and formations that simultaneously embody, reproduce and negotiate the structural locations of their subjects

Developing effective practice learning for tomorrow's social workers

This paper considers some of the changes in social work education in the UK, particularly focusing on practice learning in England. The changes and developments are briefly identified and examined in the context of what we know about practice learning. The paper presents some findings from a small scale qualitative study of key stakeholders involved in practice learning and education in social work and their perceptions of these anticipated changes, which are revisited at implementation. The implications for practice learning are discussed

Longitudinal flow evolution and turbulence structure of dynamically similar, sustained, saline density and turbidity currents

Experimental results are presented concerning flow evolution and turbulence structure of sustained saline and turbidity flows generated on 0°, 3°, 6°, and 9° sloping ramps that terminate abruptly onto a horizontal floor. Two-component velocity and current density were measured with an ultrasonic Doppler velocity profiler and siphon sampler on the slope, just beyond the slope break and downstream on the horizontal floor. Three main factors influence longitudinal flow evolution and turbulence structure: sediment transport and sedimentation, slope angle, and the presence of a slope break. These controls interact differently depending on flow type. Sediment transport is accompanied by an inertial fluid reaction that enhances Reynolds stresses in turbidity flows. Thus turbidity flows mix more vigorously than equivalent saline density flows. For saline flows, turbulent kinetic energy is dependent on slope, and rapid deceleration occurs on the horizontal floor. For turbidity flows, normalized turbulent kinetic energy increases downstream, and mean streamwise deceleration is reduced compared with saline flows. The slope break causes mean bed-normal velocity of turbidity flows to become negative and have a gentler gradient compared with other locations. A reduction of peak Reynolds normal stress in the bed-normal direction is accompanied by an increase in turbulent accelerations across the rest of the flow thickness. Thus the presence of particles acts to increase Reynolds normal stresses independently of gradients of mean velocity, and sediment transport increases across the break in slope. The experiments illustrate that saline density currents may not be good dynamic analogues for natural turbidity currents