Evaluating Voluntary Measures with Spillovers: The Case of Coal Combustion Products Partnership

Traditionally, voluntary measures have been evaluated using the same framework regardless of their structure. The framework assumes that the measure provides partners with a treatment (information, research support, etc) that will not be transferred to nonpartners. In this framework, a voluntary measure is said to be worthwhile if there are significant differences between the behavior of partners and non-partners, correcting for the potential endogeneity of becoming a partner. However, voluntary measures take many different forms; some which are expected to have information transfers (spillovers) to non-partners. The Coal Combustion Products Partnership (C2P2) is a voluntary program to increase the re-use of coal combustion products (CCP) using a structure that is likely to provide spillovers to non-partners. This paper evaluates C2P2 and tests whether program spillovers are affecting non-partners' behavior. Results suggest that the traditional interpretation would find this program unsuccessful, however when spillovers are considered, evidence points to a successful program.