## BERG working paper series

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#### Keywords

- Capital-Asset-Pricing Modell ; Mehragentensystem ; VolabilitÃ¤t ; Online-Publikation (1) (remove)

83

The paper proposes an elementary agent-based asset pricing model that, invoking the
two trader types of fundamentalists and chartists, comprises four features: (i) price determination
by excess demand; (ii) a herding mechanism that gives rise to a macroscopic
adjustment equation for the market fractions of the two groups; (iii) a rush towards fundamentalism
when the price misalignment becomes too large; and (iv) a stronger noise
component in the demand per chartist trader than in the demand per fundamentalist
trader, which implies a structural stochastic volatility in the returns. Combining analytical
and numerical methods, the interaction between these elements is studied in the
phase plane of the price and a majority index. In addition, the model is estimated by
the method of simulated moments, where the choice of the moments reflects the basic
stylized facts of the daily returns of a stock market index. A (parametric) bootstrap
procedure serves to set up an econometric test to evaluate the modelâ€™s goodness-of-fit,
which proves to be highly satisfactory. The bootstrap also makes sure that the estimated
structural parameters are well identified.