A top challenge facing policymakers today is how to raise total factor productivity, the key driver of living standards over the long term. Chapter 2: Upgrading the Tax System to Boost Productivity of the Fiscal Monitor titled "Achieving More with Less" makes the case that upgrading a country's tax system is important to boosting productivity because it can reduce distortions that prevent resources from going to where they are most productive.
http://www.imf.org/en/Publications/FM/Issues/2017/04/06/fiscal-monitor-april-2017
