Australian consumers, who can now buy unbranded milk at $1 per litre at Coles and Woolies, may be surprised by news that milk prices are rising across the world, as reported in Businessweek:

Feb. 14 (Bloomberg) — High milk prices are “the new normal” and increased global commodity demand, led by emerging markets, is set to boost them further, according to Fonterra Cooperative Group Ltd., the world’s largest dairy exporter.

Whole-milk powder prices will likely remain at least 50 percent above their historical averages in the longer term, Chief Executive Officer Andrew Ferrier said in an interview today from Auckland.

Ferrier’s forecast adds to signs of quickening global food inflation as rising incomes in emerging markets such as China spur greater consumption of dairy and meat products.

Clearly the tactics of Coles and Woolies are unsustainable over the long-term.