The possibility of statistical evaluation of the market completeness and incompleteness is investigated for continuous time diffusion stock market models. It is well known that market completeness is not a robust property: a complete market model can be made incomplete via small random deviations of the coefficients  . The paper shows that market incompleteness is also non-robust: small deviations can convert an incomplete model into a complete one. More precisely, it is shown that, for any incomplete market model from a wide class of models, there exists a complete market model with an arbitrarily close paths of the stock prices  . This leads to the counterintuitive conclusion that the incomplete markets are indistinguishable from the complete markets in the terms of the price statistics.
The possibility of statistical evaluation of the market completeness and incompleteness is investigated for continuous time diffusion stock market models. It is known that the market completeness is not a robust property: small random deviations of the coefficients convert a complete market model into a incomplete one . The paper shows that market incompleteness is also non-robust: small deviations can convert an incomplete model into a complete one. More precisely, it is shown that, for any incomplete market from a wide class of models, there exists a complete market model with arbitrarily close paths of the stock prices and the market parameters . This leads to a counterintuitive conclusion that the incomplete markets are indistinguishable from the complete markets in the terms of the market statistics.
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a complete market model can be made incomplete via
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