1,651 research outputs found
Inside Money, Procyclical Leverage, and Banking Catastrophes
We explore a model of the interaction between banks and outside investors in
which the ability of banks to issue inside money (short-term liabilities
believed to be convertible into currency at par) can generate a collapse in
asset prices and widespread bank insolvency. The banks and investors share a
common belief about the future value of certain long-term assets, but they have
different objective functions; changes to this common belief result in
portfolio adjustments and trade. Positive belief shocks induce banks to buy
risky assets from investors, and the banks finance those purchases by issuing
new short-term liabilities. Negative belief shocks induce banks to sell assets
in order to reduce their chance of insolvency to a tolerably low level, and
they supply more assets at lower prices, which can result in multiple
market-clearing prices. A sufficiently severe negative shock causes the set of
equilibrium prices to contract (in a manner given by a cusp catastrophe),
causing prices to plummet discontinuously and banks to become insolvent.
Successive positive and negative shocks of equal magnitude do not cancel;
rather, a banking catastrophe can occur even if beliefs simply return to their
initial state. Capital requirements can prevent crises by curtailing the
expansion of balance sheets when beliefs become more optimistic, but they can
also force larger price declines. Emergency asset price supports can be
understood as attempts by a central bank to coordinate expectations on an
equilibrium with solvency.Comment: 31 pages, 10 figure
The "New" Science of Networks
In recent years, the analysis and modeling of networks, and also networked
dynamical systems, have been the subject of considerable interdisciplinary
interest, yielding several hundred papers in physics, mathematics, computer science,
biology, economics, and sociology journals (Newman 2003c), as well as a number of
books (Barabasi 2002, Buchanan 2002,Watts 2003). Here I review the major findings
of this emerging field and discuss briefly their relationship with previous work in the
social and mathematical sciences
The diminishing state of shared reality on US television news
The potential for a large, diverse population to coexist peacefully is
thought to depend on the existence of a ``shared reality:'' a public sphere in
which participants are exposed to similar facts about similar topics. A
generation ago, broadcast television news was widely considered to serve this
function; however, since the rise of cable news in the 1990s, critics and
scholars have worried that the corresponding fragmentation and segregation of
audiences along partisan lines has caused this shared reality to be lost. Here
we examine this concern using a unique combination of data sets tracking the
production (since 2012) and consumption (since 2016) of television news content
on the three largest cable and broadcast networks respectively. With regard to
production, we find strong evidence for the ``loss of shared reality
hypothesis:'' while broadcast continues to cover similar topics with similar
language, cable news networks have become increasingly distinct, both from
broadcast news and each other, diverging both in terms of content and language.
With regard to consumption, we find more mixed evidence: while broadcast news
has indeed declined in popularity, it remains the dominant source of news for
roughly 50\% more Americans than does cable; moreover, its decline, while
somewhat attributable to cable, appears driven more by a shift away from news
consumption altogether than a growth in cable consumption. We conclude that
shared reality on US television news is indeed diminishing, but is more robust
than previously thought and is declining for somewhat different reasons
Acceptability and Feasibility of Portable Eye-Tracking Technology within a Children’s Dynamic Sport Context:An Exploratory Study with Boys Who Play Grassroots Football
Teaching practices are moving from decontextualised to more representative curricula. Although this is argued to be a positive step, low motor competence is a continual issue in primary-aged school children. One methodological approach to investigate ways to improve motor competence, eye tracking, is moving to more representative tasks. So far, eye-tracking research using static activities has demonstrated a positive association between motor competence and earlier fixation and longer duration. However, this research has been constrained to laboratory settings and tasks, or discrete activities (e.g., throw and catch). This study seeks to understand how to conduct more representative eye-tracking research in primary school-aged children. To this end, thirteen 10–11-year-old children were fitted with an eye-tracker during a typical football coaching session. Children were asked acceptability-based questions, and eye-gaze data were captured to illustrate what children attended to under a representative dynamic football-based activity. Based on the voices of children and captured eye-gaze data, six practical implications for research in this population are proposed: (1) conduct eye-tracking research indoors (where possible); (2) ensure long hair or fringes are secured so as not to obscure line of sight; (3) run the same activity to increase comparability across children wearing the eye-tracker; (4) use a properly fitted backpack (if a backpack is to be used); (5) assure children about the capability and hardiness of the eye-tracker, as they do not need to change the way they move; (6) explain there may be some discomfort with the nose clip, head strap, and battery weight and ensure that children wish to continue
Pre-registration for Predictive Modeling
Amid rising concerns of reproducibility and generalizability in predictive
modeling, we explore the possibility and potential benefits of introducing
pre-registration to the field. Despite notable advancements in predictive
modeling, spanning core machine learning tasks to various scientific
applications, challenges such as overlooked contextual factors, data-dependent
decision-making, and unintentional re-use of test data have raised questions
about the integrity of results. To address these issues, we propose adapting
pre-registration practices from explanatory modeling to predictive modeling. We
discuss current best practices in predictive modeling and their limitations,
introduce a lightweight pre-registration template, and present a qualitative
study with machine learning researchers to gain insight into the effectiveness
of pre-registration in preventing biased estimates and promoting more reliable
research outcomes. We conclude by exploring the scope of problems that
pre-registration can address in predictive modeling and acknowledging its
limitations within this context
Plasma Magnetosphere Formation Around Oscillating Magnetized Neutron Stars
The notion of death line of rotating pulsars is applied to model of
oscillating neutron stars. It is shown that the magnetosphere of typical
non-rotating oscillating stars may not contain secondary plasma to support the
generation of radio emission in the region of open field lines of plasma
magnetosphere.Comment: Accepted for publication in Astrophysics & Space Scienc
Evaluating the scale, growth, and origins of right-wing echo chambers on YouTube
Although it is understudied relative to other social media platforms, YouTube
is arguably the largest and most engaging online media consumption platform in
the world. Recently, YouTube's outsize influence has sparked concerns that its
recommendation algorithm systematically directs users to radical right-wing
content. Here we investigate these concerns with large scale longitudinal data
of individuals' browsing behavior spanning January 2016 through December 2019.
Consistent with previous work, we find that political news content accounts for
a relatively small fraction (11%) of consumption on YouTube, and is dominated
by mainstream and largely centrist sources. However, we also find evidence for
a small but growing "echo chamber" of far-right content consumption. Users in
this community show higher engagement and greater "stickiness" than users who
consume any other category of content. Moreover, YouTube accounts for an
increasing fraction of these users' overall online news consumption. Finally,
while the size, intensity, and growth of this echo chamber present real
concerns, we find no evidence that they are caused by YouTube recommendations.
Rather, consumption of radical content on YouTube appears to reflect broader
patterns of news consumption across the web. Our results emphasize the
importance of measuring consumption directly rather than inferring it from
recommendations.Comment: 29 pages, 21 figures, 15 table
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