For equity u can write about our "Progressive Taxation System" where you pay more tax as your income rises - ie the progressive tax brackets which you can get from the ato website.
for simplicity use this example: back in the days before GST, all goods were taxed and what's worse is that the tax rates were different across most products. E.g. normal milk = no tax. flavoured milk = __% tax. but if you bought milkshakes that would have a different percentage of tax. get the point? how complex is that? and the stupid thing is that conusmers didn't know how much percentage tax they were paying on each product.
but in 2001 the GST was introduced. Even though this is a Regressive Tax System, it introduced simplicity in the tax system --> you pay a flat rate of 10% tax on each product except simple household necessities like plain milk and bread. this way, everyone pays tax, the tax rate is equal on every product (even though its not equal when you consider people's incomes; also some products like alcohol and tobacco are taxed heavily for obvious reasons).
I don't know about efficiency but the GST could also be an example of efficiency because some people falsify their incomes to the ATO and therefore pay less tax (under the counter sales, family businesses etc). People still do that but this is counteracted by every single person paying GST. This created efficiency in a sense that everyone pays tax.
woah there's a some light reading for you lol....
but i suggest you further go ahead and do your research - im sure the textbook prolly talks about gst and progressive tax system. also check out
www.mrwood.com . also check out
www.ato.gov.au for difference btwn tax rates in 2006/07, 2007/08 and 2008/09.
ohhh since the assessment is about tax reform, you may also talk abou the recent tax cuts passed down in teh last 3 federal budgets to both high (under Howard) and low (under Rudd) income earners. In a sense the tax cuts to high income earners have created inequity, and tax cuts to low income earners have created equity to a certain extent.
best of luck!
