Minimum Entropy Calibration of Asset-Pricing Models
Marco Avellaneda
IJTAF, 1999
We present an algorithm for calibrating
asset-pricing models to benchmark prices. The algorithm computes the probability
that minimizes the relative entropy with respect to a prior and satisfies
and finite number of moment constraints. These constraints arise from fitting
the model to the prices of benchmark instruments. Generically, there exists
a unique solution which is stable, i.e. depends smoothly on the input prices.
We study the sensitivities of the values of contingent claims with respect
to variations in the benchmark prices. We find that the sensitivities
can be interpreted as regression coefficients of the payoffs of the
contingent claims on the set of payoffs of the benchmark instruments, under
the risk-neutral measure. We also show that the minimum-entropy algorithm
is a special case of a general class of algorithms for calibrating asset-pricing
models based on stochastic control and convex optimization. As an illustration,
we use minimum-entropy to construct a smooth curve of instantaneous forward
rates from US LIBOR swap/FRA data and to study the corresponding sensitivities
of fixed-income instruments to variations in input prices.