I. Background
The ground-breaking monumental piece
of Wealth of Nation published in 1776 by Adam Smith paved the way for economics
to distance itself from the moral
science and established itself as an independent discipline. The gradual
introduction of mathematics and statistics into this discipline further alienated
it from other social sciences¡Xoften perceived as soft sciences for the wrong
reason¡Xand aligned itself with other commonly perceived hard sciences¡Xalso
for the wrong reason, though¡Xsuch as physics and biology.
The development of information science, computer technology and artificial
intelligence since the mid-twentieth century has created further niche that
economics can benefit from. The significance of such niche can be perceived
in two ways. The first is the advancement in research methodology which establishes
simulation as a third approach¡Xother than the currently mainstream approaches
of theory and history (i.e., empirical studies)¡Xin the exploration of scientific
knowledge. The second is the advancement in tackling the decades-old, if
not centuries-old, problem of the interface between micro phenomenon and
macro phenomenon¡Xin economics, such an micro-macro interface issue can be
best described as the microfoundation of macroeconomics. When humanity is
perceived as a macro phenomenon waiting for exploration and explanation,
human behaviors can then be programmed in ways¡Xwhile relying on biological
sciences and human experiments such as neuroeconomics and experimental economics
for guidance¡Xto the very bottom of each and every individual (i.e., agent)
with minimum consideration of the human factors that administer our interactions
with others. Simulated interactions among the agents can then be observed
and compared with real life observations for further investigation. Moreover,
on-line experiments conducted on real agents (i.e., human beings) can even
be joined with the participation of software agents so that the ¡§intelligence¡¨
of such software agents as compared with real agents can be determined and
later be feedback into the development of future software agents.
Basically there is no limit on how this new approach can be applied and what
area it can be applied to. When applied to social phenomena happening everyday
surrounding everyone, it leads us to a new and different strand of social
sciences called computational social sciences. The purpose of the following
proposed NCCU Summer School on Computational Social Sciences, jointly proposed
by faculty members from three different departments under the coordination
of the AI-ECON Research Center of the Department of Economics, is exactly
meant to propose and promote the development of computational social sciences
in Taiwan. It is hoped that our efforts in introducing this area of research
which is relatively new in Taiwan would broaden our understanding of it and
invite more interested researchers to put efforts in it.
II. The Structure of the Summer School
A. Artificial Societies:
Herbert Simon, the winner of the Nobel Prize Award in Economics (1978),
argued that social sciences are the ¡¥hard¡¦ science in his 1987 publication
¡§Giving the soft science a hard sell¡¨. The social sciences are so hard
because we often need to make some serious assumptions to simplify the
complexity of our questions. So in the economic filed, we need to use the
representative agent to conduct with the economic issues and then get the
conclusions. But we could not deal with the problems of why we could use¡¨
representative agent¡¨ to consider our question? Do all persons really have
the homogeneous utility function or preference? Do all people behave as
the same routines?
Traditional thought in the social sciences (especially in the economics
filed) always use the ¡§top-down¡¨ framework, like above thought methods,
to tell us how to solve or observe the things in the realistic economic
environments. But all the situations in these sequences of ideas, we always
just get so relative static and drab conclusions, not so realistic, and
could not let us know more about what operating process does the real-world
and how to conduct with them?
Accompanying with the developing of the computer technologies, now we
could use the Agent-based architecture to uncover many black-box that we
could not deal with before in the social science. Agent-based computing
allows us to use the ¡§bottom-up¡¨ framework and simulation to simulate what
our real-world potentially to be and change. In the Agent-based architecture,
we could use the computer to model the agent and their behavioral rule,
and then start to study what the human social phenomena, including trade,
migration, group formation, combat, interaction with an environment, transmission
of culture, propagation of disease, population dynamics and so on. By the
Agent-based architecture, it really enriches our abilities to deal with
the questions with all kinds of possibility deeply.
In the 1996, Epstein and Axtell design the model which named ¡§Sugarscape¡¨
to simulate the relatively simple CA or other ¡§emergent¡¨ simulations which
deal with one or two major social dynamics as a very general level like
trading behaviors, food acquisition, or residential segregation. And through
the variable network relationship between different agents, the model generates
numerous data and finds the different situations with the artificial-life
research. By those findings, they bring up some important conclusions in
their book (1996,¡¨growing artificial societies¡¨). Beside this, recently
there are so many applications to use the same thought and methods to observe
the spread of the HIV pandemic or civilization collapse and so on.
By so many Agent-based applications with the topic of ¡§artificial society¡¨,
it may be useful to let us enter into a brief thinking that what the function
of the ¡§artificial society?¡¨ and if we could let the society science become
more not so hard by ¡§artificial society?¡¨ or not?
B. Agent-Based Computational Finance:
The agent-based computational finance is a growing research field, and
one of the popular fields to which agent-based modeling are applied. Agent-based
modeling is to analyze evolving systems of autonomous interacting and heterogeneous
agents. Starting from initial conditions, the computational model evolves
over time as each of its agents repeatedly changes her behavior through
interactions and learning. Simulations of the model produce the dynamics
of the market as well as agents. As a result, we can possibly analyze how
agents¡¦ behavior is related to the market dynamics. The analysis of agent-based
models is a bottom-up approach to the study of the markets to be analyzed.
Applications of such agent-based modeling to financial markets are particularly
appealing for some reasons. First, such an applied field, often called
Agent-based computational finance, provides a mechanics to understand empirical
features in financial markets. It is well known that the financial time
series have many interesting puzzles that are not fully understood. For
example, the financial time series contains volatility clustering, fat
tails, ARCH dependence of the returns, long-memory of trading volume, and
so on. Those empirical features do not match traditional macroeconomics
approaches. Agent-based computational finance has potential for solving
those puzzles as shown in many papers (e.g., LeBaron et al. in Journal
of Economic Dynamics and Control 1999). The models formulated in agent-based
computational finance, which include agents¡¦ heterogeneity and learning
and adaptation mechanism, are well suited for explaining puzzles in financial
markets.
The second reason is that financial markets provide plentiful datasets.
For example, prices and volume series for more than 30 years at different
frequency are normally available to researchers. In addition, we can possibly
get experimental data so that we can use it for calibrating agent behavior.
Those datasets make it possible for researchers to test and calibrate agent-based
models on financial markets. For this reason, financial markets also fit
for applying agent-based modeling.
C. Agent-Based Social Networks:
All human actions that involve the participation or interaction of two
or more people are necessarily network phenomena in nature. Current researches
suggest that there are some interesting issues or special characteristics
that can be found in the social networks in our daily lives such as the
small world phenomenon, the centrality issue, the effect of local network
structure, and the dependency issue of a network-formation mechanism, etc.
By looking at these phenomena, we are able to see how people interact with
each other, how the chains of relations are formed and how other important
human activities are coordinated and achieved.
The biggest problem in social network researches is the difficulty in
getting data related to the ¡§network relations¡¨ because this will often
require the revelation of a lot of particular knowledge or even inside
information pertaining to the network in concern. This problem becomes
even worse when the network gets too large. To circumvent such difficulty,
one can either look into the internet or adopt an agent-based approach
in the research. The internet itself is a big social network and there
is no limit on how big it can grow. Modern web technology in the so-called
Web 2.0 or even Web 3.0 era enables us to trace the network relations from
websites. Citations and cross-references so frequently appearing in web
logs and databases provide the best example of how we can reestablish a
social network from surfing the internet via. the application of software
agents.
The concept of social network, its meaning when applied to the internet,
and the software agent technology are then the three focal subjects that
we would like to include in the summer school.