performance of individuals “treated” by particular programs. Clearly, not all trade-related programs can be amenable to such “treatment-effect” methodologies. The easiest are exportpromotion programs that target individual firms..<sup>27</sup> Even in the limited areas where their application is relatively straightforward, applications of “clinical” impact evaluation methods to trade-related programs have so far been limited. They provide no evaluation of spillover effects—even though spillovers are key to the justification of public intervention. Moreover, like all clinical impact evaluations, they have uncertain “external validity”, as what works in one setting may not work in another. Notwithstanding these and other caveats that have been extensively discussed in the literature (Rodrik 2008), they offer a valuable tool to understand what works and what does not. In particular, when carefully thought out, they can help identify which _components_ of assistance programs work best. That is, beyond their contribution to general accountability, they have the power to generate useful knowledge to renew the factual basis on which to base policy advice and donor practice.

Investment in data and analysis should span work at both the macro and micro levels. An agenda in this area must center on a framework for rigorous evaluation of aid-for trade-projects, empirical research on aid impact evaluation, drawing on macro datasets from the CRS OECD databases and micro-data from projects that are implemented by development agencies. Country and/or regional analyses of aid for trade effectiveness are needed to assess how types of aid for trade funds are spent in relation to their returns, as measured by increased trade flows, lower trade costs, etc. Data on trade costs could be collected from a variety of sources, including trade support institutions, customs authorities, and international transport companies. Detailed data will be needed to assess policies related to specific aid for trade interventions – e.g. support for industrial upgrading, certification of firms (ISO 9000), or technical assistance for transport logistics (Wilson, 2010).

At the country- and regional level, the private sector has an important role to play monitoring and evaluation, as directly affected and concerned firms, industries and associations have access to information regarding the effectiveness of efforts to address specific trade-related bottlenecks and constraints.

# **6. Moving the Agenda Forward**

The G-20 is uniquely positioned to support specific actions to expand global trade. The fragile economic recovery – combined with the need to strengthen the international trading system in support of sustainable and inclusive growth and employment – place the aid for trade initiative at the forefront of policy importance. In addition to delivering on the commitments made in Gleneagles and Hong Kong on expanding aid for trade flows, there are four strategic themes that a G-20 “Action Agenda on Aid for Trade and Development” might support:

1. Establish a **_platform for capacity-building and transfer of knowledge to improve regulation of producer services and the operation of network infrastructure_** . A coordinated program of assistance and knowledge exchange that includes active involvement of middle income G20 countries could do much to increase the rate of return

> 27 See Volpe and Carballo (2008) for an evaluation of Peru’s export-promotion program.

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