Exactly. The point of this sort of tax should not be to collect revenue, it should be to ensure that non-biodegradable bags are being disposed of correctly. To the extent that this is not happening, any bag tax is malfunctioning. Such a tax is either insufficient or poorly-designed. (Our city just banned chain stores from giving out plastic bags under 4 mils thick, and stores now give out paper and sell re-usable bags.)