2,478 research outputs found
Estimating the Value of Medal Success at the 2010 Winter Olympic Games
We estimate Canadiansâ willingness to pay (WTP) for success by Team Canada in the 2010 Winter Olympics. The Canadian government subsidized elite athletes in the run up to the 2010 Games through the Own the Podium program, which was designed to increase Canadaâs medal count. WTP estimates from a contingent valuation method (CVM) study using data from nationally representative surveys before and after the Games suggest that Own the Podium generated intangible benefits of between 3 and 5 times its cost. The aggregate value of the intangible benefits generated by the program was between 3.4 billion. Key Words: Olympic Games, contingent valuation method, willingness to pay
Temporal Evolution of Financial Market Correlations
We investigate financial market correlations using random matrix theory and
principal component analysis. We use random matrix theory to demonstrate that
correlation matrices of asset price changes contain structure that is
incompatible with uncorrelated random price changes. We then identify the
principal components of these correlation matrices and demonstrate that a small
number of components accounts for a large proportion of the variability of the
markets that we consider. We then characterize the time-evolving relationships
between the different assets by investigating the correlations between the
asset price time series and principal components. Using this approach, we
uncover notable changes that occurred in financial markets and identify the
assets that were significantly affected by these changes. We show in particular
that there was an increase in the strength of the relationships between several
different markets following the 2007--2008 credit and liquidity crisis.Comment: 15 pages, 10 figures, 1 table. Accepted for publication in Phys. Rev.
E. v2 includes additional section
Dynamic communities in multichannel data: An application to the foreign exchange market during the 2007--2008 credit crisis
We study the cluster dynamics of multichannel (multivariate) time series by
representing their correlations as time-dependent networks and investigating
the evolution of network communities. We employ a node-centric approach that
allows us to track the effects of the community evolution on the functional
roles of individual nodes without having to track entire communities. As an
example, we consider a foreign exchange market network in which each node
represents an exchange rate and each edge represents a time-dependent
correlation between the rates. We study the period 2005-2008, which includes
the recent credit and liquidity crisis. Using dynamical community detection, we
find that exchange rates that are strongly attached to their community are
persistently grouped with the same set of rates, whereas exchange rates that
are important for the transfer of information tend to be positioned on the
edges of communities. Our analysis successfully uncovers major trading changes
that occurred in the market during the credit crisis.Comment: 8 pages, 6 figures, accepted for publication in Chao
Selection of the scaling solution in a cluster coalescence model
The scaling properties of the cluster size distribution of a system of
diffusing clusters is studied in terms of a simple kinetic mean field model. It
is shown that a one parameter family of mathematically valid scaling solutions
exists. Despite this, the kinetics reaches a unique scaling solution
independent of initial conditions. This selected scaling solution is marginally
physical; i.e., it is the borderline solution between the unphysical and
physical branches of the family of solutions.Comment: 4 pages, 5 figure
Structural approaches to modeling the impact of climate change and adaptation technologies on crop yields and food security
Article purchasedAchieving and maintaining global food security is challenged by changes in population, income, and climate, among other drivers. Assessing these threats and weighing possible solutions requires a robust multidisciplinary approach. One such approach integrates biophysical modeling with economic modeling to explore the combined effects of climate stresses and future socioeconomic trends, thus providing a more accurate picture of how agriculture and the food system may be affected in the coming decades. We review and analyze the literature on this structural approach and present a case study that follows this methodology, explicitly modeling drought and heat tolerant crop varieties. We show that yield gains from adoption of these varieties differ by technology and region, but are generally comparable in scale to (and thus able to offset) adverse effects of climate change. However, yield increases over the projection period are dominated by the effects of growth in population, income, and general productivity, highlighting the importance of joint assessment of biophysical and socioeconomic drivers to better understand climate impacts and responses
Spin chirality on a two-dimensional frustrated lattice
The collective behavior of interacting magnetic moments can be strongly
influenced by the topology of the underlying lattice. In geometrically
frustrated spin systems, interesting chiral correlations may develop that are
related to the spin arrangement on triangular plaquettes. We report a study of
the spin chirality on a two-dimensional geometrically frustrated lattice. Our
new chemical synthesis methods allow us to produce large single crystal samples
of KFe3(OH)6(SO4)2, an ideal Kagome lattice antiferromagnet. Combined
thermodynamic and neutron scattering measurements reveal that the phase
transition to the ordered ground-state is unusual. At low temperatures,
application of a magnetic field induces a transition between states with
different non-trivial spin-textures.Comment: 7 pages, 4 figure
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