Prime Minister Tony Abbott's success at clinching long-sought-after free trade deals with our major trading partners will expand Australian export markets and make imports cheaper. However, it has also made his budget task harder in the immediate term – to the tune of as much as $2.4 billion in tariff revenue foregone.

Two separate pieces of analysis, one last year by the public service, and one more recently by a public policy advisory panel, have identified revenue shortfalls associated with the deals mostly flowing from the removal or reduction of import tariffs.

This fiscal downside is the little known aspect of the otherwise positive stories about freer trade, more jobs, lower prices, and better growth.

In the case of the recently agreed, but yet to be signed, Economic Partnership Agreement with Japan, the main concession from Canberra came in the form of the removal of the 5 per cent mark-up on Japanese cars sold in Australia.

Under the deal, that tariff will be removed as soon as the deal becomes operative on three-quarters of imported Japanese vehicles and quickly phased down to zero for the remaining 25 per cent.