No. 3 - Department of Treasury - The Western Australian Government

Western Australian Economic Summary2006 No.3In contrast, economic impact analysis should not be used to assess the meritof a proposal. In a report prepared for the Western Australian EconomicRegulation Authority (ERA), Marsden Jacob Associates (MJA) notes the roleof economic impact analysis as:The purpose of economic impact analysis is to quantify and describe thepertinent impacts (such as the number of jobs created during theconstruction period of a major piece of infrastructure or the amount ofincome generated). However, these aggregates describe economic impacts anddo not themselves indicate the magnitude of the benefits and costs andwhether the project is desirable from a social point of view.MJA, 2006, p. 2Economic impact analysis can reveal interesting things that will happen inresponse to a proposal, but it cannot tell policy makers whether thatproposal will make Western Australians better of and is worth pursuing 1 .However, many of the CGE analyses presented to the State Government tothis point in time are in fact impact analyses, and do not inform on thepotential welfare gain from assisting a project.Welfare measuresIf we are undertaking welfare analysis, then the final figure (or figures) thatwe pluck from the thousands of results produced in a CGE model must be areasonable approximation of economic welfare. In this regard, thecommonly used figures for Gross Domestic Product (GDP) at the nationallevel and Gross State Product (GSP) at the State level are not good measuresof economic welfare.Changes in GDP and GSP can be offset by changes in an economy’s terms oftrade and, importantly for foreign-financed projects, by increased foreignownership. There are also problems with the Divisia problem (Dixon andRimmer, 2002, p. 25), where changing weights can lead to a change in GDPwithout a change in production for any specific commodity.Dixon and Rimmer note that real consumption (private and public) is abetter indicator, but still suffers from the Divisia index problem. Instead,they recommend Laspeyres or Paasch cost differences (pp. 210-211).Alternatively, Layman (2004, p. 21) argued that, while Laspeyres or Paaschcost differences were technically superior, consumption was a more practicaland acceptable measure for explanation to policy makers.At the State level in a regional CGE model, large population shifts relative tothe base case are common when an economic shock (such as the advent of amajor project) occurs in just one region (Wilson, 2004, p. 2). Such shifts meanjust about any project can make the economy bigger, but this does notnecessarily mean that the residents of the economy are better off.1 Impact analysis can be useful for analysing adjustment costs of a project or policy.80 Department of Treasury and Finance