fe45a3b1_lian_Broadcasting_Corporation___Definition
[Term] Tax expenditures [Definition] 
Tax expenditures are sources of revenue the government goes without due to tax concessions. While they are not government spending, they represent significant losses of potential revenue for the government. In 2013-14 expenditures hit the budget bottom line to the tune of $115 billion, and while some of this is offset by increases in productivity and increased spending, it remains a significant source of potential revenue the government is missing out on. Among the most well-known examples of tax expenditures are superannuation concessions and the capital gains tax exemption on the family home.
Budget 2014: Tony Abbott opens door to 'horse-trading' with minor parties in Senate to pass key measures - Federal Budget 2014 - ABC News (Australian Broadcasting Corporation)
Definition