This chapter begins by providing a historical account of the liberalization in regulated sectors. This sets the stage for a discussion on how productivity and efficiency measures have become both a goal and a tool in some of these sectors. The chapter also presents an extensive overview of case studies both across industries and countries. Subsequently, it provides a review on how the literature has tried to deal with the many empirical challenges related to measuring productivity and efficiency. Finally, it makes the case for a switch to the structural ETC approach (first economics, then technology, and finally empirical challenges) to performance measurement in policy areas as a solution to many of the issues surveyed in the chapter.