问一道题：NO.PZ202001080100003801

问题如下：

a. What additional model would you estimate to implement the Chow test?

选项：

解释：

The original model is $Y_i = \alpha + \beta_S ln SALES_i + \beta_B BTM_i + \beta_E EBITDA_i + \beta_P NetPPE_i + \epsilon_i$. The Chow test allows the slope coefficient to vary in the energy industry, so that the extended model is

$Y_i = \alpha + \beta_S ln SALES_i + \beta_B BTM_i + \beta_E EBITDA_i + \beta_P NetPPE_i + \gamma_S I_{Energy}*ln SALES_i +\gamma_B I_{Energy}*BTM_i+\gamma_E I_{Energy}*EBITDA_i+\gamma_P I_{Energy}*NetPPT_i+\epsilon_i$.

where $I_{Energy}$ is a dummy that takes the value 1 if a firm is in the energy industry.