The commission was asked by the government to undertake modelling of the economy-wide effects of assistance options and scenarios identified by the current Bracks Review of Australia's automotive industry. The options cover a number of combinations of tariffs and levels of assistance provided under the Automotive Competitiveness and Investment Scheme.  Assessing economy-wide effects of any policy intervention requires identification and summation of all the costs and benefits that flow from it. For instance, changes in industry assistance alter the economic returns from different activities. This induces changes in the pattern of resource allocation across the economy (requiring adjustments by labour and capital), as well as levels of investment and, through various mechanisms, productivity. These changes in turn affect industry output, exports and imports, prices (including the ‘terms of trade’) and, hence, national production and income.