addressing these barriers requires an integrated approach across environment economic and social domains and often close coordination among different levels of government clear stable and credible longterm environmental energy transport and infrastructure policy signals are important drivers of investment and innovation kaminker c et al corfeemorlot j et al criscuolo c and c menon oecd and oecd b in addition barriers to investment and innovation can often be addressed with revision to existing policy regulation and tax settings kaminker c et al