An Empirical Examination of the Pricing of American Put Options
事后比较了美式与欧式看跌期权定价模型的准确性，发现Geske-Johnson美式模型比Black-Scholes欧式模型更接近市场价格，但两者均低估了期权价值。
This study is an ex post performance test comparing the accuracy of an American model to a European model for valuing listed options. Specifically, the Geske and Johnson American put valuation model is compared with the Black and Scholes European put model. On average, both models undervalue, relative to market prices, put options. However, the Geske and Johnson model values are significantly closer to market prices than are the Black and Scholes values.