what is gamma what is the ols for gamma what model is used to estimate the average stock price which model uses gamma as dummy when the dummy is zero, which model biases standard errors and which one is zero? time series model what is gamma_i used for ols when an ols is used to approximate a time series, the bias is what is the standard error in a time series? what is the difference between the dummy and the time series model in the ols equation which model to use for a cross sectional gamma model which of the following models is an example of a cross section model? what is the gamma vector for x? which of the following is an example of a time-series model that is not biased which econometric model has standard error why are standard errors in ols what type of model is $epsilon_ittepsilon_itjt$ when an ols curve is constructed ols time series model what is the standard error of the second ols model