In this paper it is assumed that capital is putty-clay, that technical progress is embodied, and that the ex ante production function is CES in form. In this setting the Monte Carlo technique is used to examine the small-sample properties of several neoclassical estimators of the ex ante capital intensity parameter and of the ex ante elasticity of substitution. Central to the analysis a putty-clay model in which the production process is stochastic. This model suggests a regression specification which is consistent with the assumed nature of capital, and the properties of its estimators are examined.