5,170 research outputs found
Applications of physics to finance and economics: returns, trading activity and income
This dissertation reports work where physics methods are applied to financial
and economical problems. The first part studies stock market data (chapter 1 to
5). The second part is devoted to personal income in the USA (chapter 6).
We first study the probability distribution of stock returns at mesoscopic
time lags (return horizons) ranging from about an hour to about a month. For
mesoscopic times the bulk of the distribution (more than 99% of the
probability) follows an exponential law. At longer times, the exponential law
continuously evolves into Gaussian distribution.
After characterizing the stock returns at mesoscopic time lags, we study the
subordination hypothesis. The integrated volatility V_t constructed from the
number of trades process can be used as a subordinator for a Brownian motion.
This subordination is able to describe approximatly 85% of the stock returns
for time lags that start at 1 hour but are shorter than one day. Finally, we
show that the CIR process describes well enough the empirical V_t process, such
that the corresponding Heston model is able to describe the log-returns x_t
process, with approximately the maximum quality that the subordination allows.
Finally, we study the time evolution of the personal income distribution. We
find that the personal income distribution in the USA has a well-defined
two-income-class structure. The majority of population (97-99%) belongs to the
lower income class characterized by the exponential Boltzmann-Gibb(``thermal'')
distribution, whereas the higher income class (1-3% of population) has a Pareto
power-law (``superthermal'') distribution. We show that the ``thermal'' part is
stationary in time.Comment: 24 pages and 45 figures. PhD thesis presented to the committee
members on May 10th 2005. This thesis is based on 3 published papers with one
chapter (chapter 5) with new unpublished result
Temporal evolution of the "thermal" and "superthermal" income classes in the USA during 1983-2001
Personal income distribution in the USA has a well-defined two-class
structure. The majority of population (97-99%) belongs to the lower class
characterized by the exponential Boltzmann-Gibbs ("thermal") distribution,
whereas the upper class (1-3% of population) has a Pareto power-law
("superthermal") distribution. By analyzing income data for 1983-2001, we show
that the "thermal" part is stationary in time, save for a gradual increase of
the effective temperature, whereas the "superthermal" tail swells and shrinks
following the stock market. We discuss the concept of equilibrium inequality in
a society, based on the principle of maximal entropy, and quantitatively show
that it applies to the majority of population.Comment: v.3: 7 pages, 5 figures, EPL style, more references adde
Exponential distribution of financial returns at mesoscopic time lags: a new stylized fact
We study the probability distribution of stock returns at mesoscopic time
lags (return horizons) ranging from about an hour to about a month. While at
shorter microscopic time lags the distribution has power-law tails, for
mesoscopic times the bulk of the distribution (more than 99% of the
probability) follows an exponential law. The slope of the exponential function
is determined by the variance of returns, which increases proportionally to the
time lag. At longer times, the exponential law continuously evolves into
Gaussian distribution. The exponential-to-Gaussian crossover is well described
by the analytical solution of the Heston model with stochastic volatility.Comment: 7 pages, 12 plots, elsart.cls, submitted to the Proceedings of
APFA-4. V.2: updated reference
Mortgage debt and entrepreneurship
We study the link between mortgage debt and entrepreneurship using a model of occupational choice and housing tenure in a setting where loans are recourse|like in the UK and several US states. Our model shows that as long as the mortgage interest rate exceeds the risk-free rate: (i) mortgage debt diminishes the likelihood of entrepreneurship by amplifying risk aversion; and (ii) the negative relation between mortgage debt and entrepreneurship increases with income volatility. Our model also shows that the link between housing equity and entrepreneurship is ambiguously signed because of competing portfolio and wealth effects. We use the British Household Panel Survey to test and confirm the model predictions, and deal with unobservable heterogeneity employing three research designs | individual fixed effects, housing-spell fixed effects, and instrumental variables. A one standard deviation increase in leverage reduces the probability of entrepreneurship by 10-20 percen
Properties of the open cluster Tombaugh 1 from high resolution spectroscopy and uvbyCaH photometry
Open clusters can be the key to deepen our knowledge on various issues
involving the structure and evolution of the Galactic disk and details of
stellar evolution because a cluster's properties are applicable to all its
members. However the number of open clusters with detailed analysis from high
resolution spectroscopy and/or precision photometry imposes severe limitation
on studies of these objects. To expand the number of open clusters with
well-defined chemical abundances and fundamental parameters, we investigate the
poorly studied, anticenter open cluster Tombaugh 1. Using precision
uvbyCaH photometry and high resolution spectroscopy, we derive the
cluster's properties and, for the first time, present detailed abundance
analysis of 10 potential cluster stars. Using radial position from the cluster
center and multiple color indices, we have isolated a sample of unevolved
probable, single-star members of Tombaugh 1. The weighted photometric
metallicity from and is [Fe/H] = -0.10 0.02, while a match to
the Victoria-Regina Str\"{o}mgren isochrones leads to an age of 0.95 0.10
Gyr and an apparent modulus of = 13.10 0.10. Radial velocities
identify 6 giants as probable cluster members and the elemental abundances of
Fe, Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Y,Ba, Ce, and Nd have been derived for both
the cluster and the field stars. Tombaugh 1 appears to be a typical inner thin
disk, intermediate-age open cluster of slightly subsolar metallicity, located
just beyond the solar circle, with solar elemental abundance ratios except for
the heavy s-process elements, which are a factor of two above solar. Its
metallicity is consistent with a steep metallicity gradient in the
galactocentric region between 9.5 and 12 kpc. Our study also shows that Cepheid
XZ CMa is not a member of Tombaugh 1, and reveals that this Cepheid presents
signs of barium enrichment.Comment: 74 pages, 15 figures, 13 tables; Accepted for publication in A
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