A regressive tax is one which places a greater burden on the poor than the rich. Tithing (on gross or net) could be seen as one such type of tax.
The subject of tithing still continues to fascinate me, as can be seen by what I’ve been reading today:
Tithing and Progressive Taxation –
The opposite view –
An evangelical Christian perspective –
A Tithing Rap –
A silly critique of tax cuts for the rich using Mormon tithing as an example –