G will

convenience compliance

Convenience (One of Adam Smith's 4 principles). 
Compliance with a tax should be easy and convenient. In the U.S., for example, compliance with income tax laws increased dramatically after a system of withholding tax payments from payrolls was introduced. 

Compliance
The effectiveness of any government depends on the willingness of the people governed to surrender or exchange a measure of control over their persons and property in return for protection and other services. Taxation is one form of this exchange.