Regressors often have heterogeneous effects in the social sciences, implying unit-specific slopes. OLS is frequently applied to these correlated coefficient models. I first show that without restrictions on the relation between slopes and regressors, OLS estimates can take any value including...

Regressors often have heterogeneous effects in the social sciences, implying unit-specific slopes. OLS is frequently applied to these correlated coefficient models. I first show that without restrictions on the relation between slopes and regressors, OLS estimates can take any value including...

The industry organization theory in the early stage emphasizes the structure-conduct-performance (SCP) paradigm, indicating that industry characteristics and structure factors influence firm performance. Accompanied by technology development and the enhancement of innovation capabilities, the...