Effect of intervention on productivity improvement (ANCOVA).
(Notes) 1. Robust standard errors in parentheses.2. ***, **, and * indicate statistical significance at the 1%, 5%, and 10% levels.3. The variables described in section 2.2.4 are used as control variables in the estimation but are omitted from the table.However, as mentioned in the previous section, the causal effects of the intervention presented in 