In response to this mandate, the CEC created a framework for conducting environmental analysis of NAFTA, one of the first ex post frameworks for the environmental assessment of trade liberalization. The framework was designed to produce a focused and systematic body of evidence with respect to the initial hypotheses about NAFTA and the environment, such as the concern that NAFTA would create a "race to the bottom" in environmental regulation among the three countries, or the hope that NAFTA would pressure governments to increase their environmental protection mechanisms. The CEC has held four symposia using this framework to evaluate the environmental impacts of NAFTA and has commissioned 47 papers on this subject. In keeping with the CEC’s overall strategy of transparency and public involvement, the CEC commissioned these papers from leading independent experts.