My tax rate is now at 6%, next month will drop to 5% (in Mullin). My pop is increasing fast (Welfare Index is 103%) and in a few hours I'll have enough worker for another corp. I'm committed to being a good partner to CERO's and I'll juggle workers as needed, and send alerts (if you wish) when one of your corps is running low on a particular material and can usually sell the material.
If you plan to build as soon as pop gets to needed level, please let me know so I won't start a state owned corp.