8,171 research outputs found
Free Cash-Flow, Issuance Costs and Stock Price Volatility
We study the issuance and payout policies that maximize the value of a firm facing both agency costs of free cash-flow and external financing costs. We find that the firm optimally issues equity. Equity distributes no dividends until a target cash level is reached, while new equity is issued when the firm runs out of cash. We characterize the process modelling the number of outstanding shares and the dynamics of the stock prices. In line with the leverage effect identified by Black (1976), we show that both the volatility of stock returns and the dollar volatility of stock prices increase after a negative shock on stock prices.
European Cyber Security System
Nowadays computer networks are widely spread in all spheres of human life.
That is why the problem of cyber security of mankind is of great importance. Today,
the European Union makes efforts to guarantee network safety in Europe by means of
increase its member states in power and international cooperation in cyber security,
including non-member countries, to prevent cyber crimes. Striving to join the
European Union, Ukraine is involved in the process of providing cyber security. This
paper examines the main strategies of EU standards in cyber security to be followed
by Ukraine as one of European countries
Measuring the effect of node aggregation on community detection
Many times the nodes of a complex network, whether deliberately or not, are
aggregated for technical, ethical, legal limitations or privacy reasons. A
common example is the geographic position: one may uncover communities in a
network of places, or of individuals identified with their typical geographical
position, and then aggregate these places into larger entities, such as
municipalities, thus obtaining another network. The communities found in the
networks obtained at various levels of aggregation may exhibit various degrees
of similarity, from full alignment to perfect independence. This is akin to the
problem of ecological and atomic fallacies in statistics, or to the Modified
Areal Unit Problem in geography. We identify the class of community detection
algorithms most suitable to cope with node aggregation, and develop an index
for aggregability, capturing to which extent the aggregation preserves the
community structure. We illustrate its relevance on real-world examples (mobile
phone and Twitter reply-to networks). Our main message is that any
node-partitioning analysis performed on aggregated networks should be
interpreted with caution, as the outcome may be strongly influenced by the
level of the aggregation.Comment: 12 pages, 5 figure
Labeling smokers' charts with a "smoker” sticker: Results of a randomized controlled trial among private practitioners
We randomly assigned private practitioners (n=393) to receiving, by mail, a box of "Smoker” stickers and a recommendation to label smokers' charts with these stickers, or to no intervention. Twenty percent of the physicians reported using the stickers and applying them on 43% of their smoking patients' charts. The intervention had no impact on physician reports of the proportion of smokers advised to quit smoking, but physicians who reported using the stickers stated that they advised more smokers to quit after the intervention (89%) than before (80%, P=.02). Thus, self-reports by physicians indicated that use of the stickers was associated with an increased proportion of smokers advised to quit. However, overall, the intervention did not modify physicians' behavio
On the strategic value of risk management
This article examines how firms facing volatile input prices and holding some degree of market power in their product market link their risk management
and production or pricing strategies. This issue is relevant in many industries ranging from manufacturing to energy retailing, where risk averse firms decide
on their hedging strategies before their product market strategies. We find that hedging modifies the pricing and production strategies of firms. This
strategic effect is channelled through the expected risk-adjusted cost, i.e., the expected marginal cost under the measure induced by investors'risk aversion,
and has diametrically opposed impacts depending on the nature of product market competition: hedging toughens quantity competition while it softens
price competition. Finally, committing to a hedging strategy is always a best response to non committing, and is a dominant strategy if firms compete à la
Hotelling
Free Cash-Flow, Issuance Costs and Stock Price Volatility
We study the issuance and payout policies that maximize the value of a firm facing both agency costs of free cash-flow and external financing costs. We find that the firm optimally issues equity. Equity distributes no dividends until a target cash level is reached, while new equity is issued when the firm runs out of cash. We characterize the process modelling the number of outstanding shares and the dynamics of the stock prices. In line with the leverage effect identified by Black (1976), we show that both the volatility of stock returns and the dollar volatility of stock prices increase after a negative shock on stock prices
The twofold debris disk around HD 113766 A - Warm and cold dust as seen with VLTI/Midi and Herschel/Pacs
Warm debris disks are a sub-sample of the large population of debris disks,
and display excess emission in the mid-IR. Around solar-type stars, very few
objects show emission features in mid-IR spectroscopic observations, that are
attributed to small, warm silicate dust grains. The origin of this warm dust
can possibly be explained either by a collision between several bodies or by
transport from an outer belt. We present and analyse new far-IR Herschel/Pacs
observations, supplemented by ground-based data in the mid-IR (VLTI/Midi and
VLT/Visir), for one of these rare systems: the 10-16 Myr old debris disk around
HD 113766 A. We improve an existing model to account for these new
observations, and better constrain the spatial distribution of the dust and its
composition. We underline the limitations of SED modelling and the need for
spatially resolved observations. We find that the system is best described by
an inner disk located within the first AU, well constrained by the Midi data,
and an outer disk located between 9-13 AU. In the inner dust belt, our previous
finding of Fe-rich crystalline olivine grains still holds. We do not observe
time variability of the emission features over at least a 8 years time span, in
a environment subjected to strong radiation pressure. The time stability of the
emission features indicates that {\mu}m-sized dust grains are constantly
replenished from the same reservoir, with a possible depletion of
sub-{\mu}m-sized grains. We suggest that the emission features may arise from
multi-composition aggregates. We discuss possible scenarios concerning the
origin of the warm dust. The compactness of the innermost regions as probed by
Midi, as well as the dust composition, suggest that we are witnessing the
outcomes of (at least) one collision between partially differentiated bodies,
in an environment possibly rendered unstable by terrestrial planetary
formation
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