126,107 research outputs found
The Predictive Power of Zero Intelligence in Financial Markets
Standard models in economics stress the role of intelligent agents who
maximize utility. However, there may be situations where, for some purposes,
constraints imposed by market institutions dominate intelligent agent behavior.
We use data from the London Stock Exchange to test a simple model in which zero
intelligence agents place orders to trade at random. The model treats the
statistical mechanics of order placement, price formation, and the accumulation
of revealed supply and demand within the context of the continuous double
auction, and yields simple laws relating order arrival rates to statistical
properties of the market. We test the validity of these laws in explaining the
cross-sectional variation for eleven stocks. The model explains 96% of the
variance of the bid-ask spread, and 76% of the variance of the price diffusion
rate, with only one free parameter. We also study the market impact function,
describing the response of quoted prices to the arrival of new orders. The
non-dimensional coordinates dictated by the model approximately collapse data
from different stocks onto a single curve. This work is important from a
practical point of view because it demonstrates the existence of simple laws
relating prices to order flows, and in a broader context, because it suggests
that there are circumstances where institutions are more important than
strategic considerations
The virtues and vices of equilibrium and the future of financial economics
The use of equilibrium models in economics springs from the desire for
parsimonious models of economic phenomena that take human reasoning into
account. This approach has been the cornerstone of modern economic theory. We
explain why this is so, extolling the virtues of equilibrium theory; then we
present a critique and describe why this approach is inherently limited, and
why economics needs to move in new directions if it is to continue to make
progress. We stress that this shouldn't be a question of dogma, but should be
resolved empirically. There are situations where equilibrium models provide
useful predictions and there are situations where they can never provide useful
predictions. There are also many situations where the jury is still out, i.e.,
where so far they fail to provide a good description of the world, but where
proper extensions might change this. Our goal is to convince the skeptics that
equilibrium models can be useful, but also to make traditional economists more
aware of the limitations of equilibrium models. We sketch some alternative
approaches and discuss why they should play an important role in future
research in economics.Comment: 68 pages, one figur
Practical applications of multi-agent systems in electric power systems
The transformation of energy networks from passive to active systems requires the embedding of intelligence within the network. One suitable approach to integrating distributed intelligent systems is multi-agent systems technology, where components of functionality run as autonomous agents capable of interaction through messaging. This provides loose coupling between components that can benefit the complex systems envisioned for the smart grid. This paper reviews the key milestones of demonstrated agent systems in the power industry and considers which aspects of agent design must still be addressed for widespread application of agent technology to occur
Impact of information cost and switching of trading strategies in an artificial stock market
This paper studies the switching of trading strategies and its effect on the
market volatility in a continuous double auction market. We describe the
behavior when some uninformed agents, who we call switchers, decide whether or
not to pay for information before they trade. By paying for the information
they behave as informed traders. First we verify that our model is able to
reproduce some of the stylized facts in real financial markets. Next we
consider the relationship between switching and the market volatility under
different structures of investors. We find that there exists a positive
relationship between the market volatility and the percentage of switchers. We
therefore conclude that the switchers are a destabilizing factor in the market.
However, for a given fixed percentage of switchers, the proportion of switchers
that decide to buy information at a given moment of time is negatively related
to the current market volatility. In other words, if more agents pay for
information to know the fundamental value at some time, the market volatility
will be lower. This is because the market price is closer to the fundamental
value due to information diffusion between switchers.Comment: 15 pages, 9 figures, Physica A, 201
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