Market studies are research projects aimed at gaining an in-depth understanding of how sectors and markets work. A market study results in a report of the findings that sets out the problems found and issues recommendations to policy makers or leads to follow-up enforcement action. We will introduce the general set-up and best practices relevant for market studies and look at available OECD, ICN and national guidance. Experts from national competition authorities will give insights into their practical experience. We will put a special emphasis on the internet economy and markets with buyer power problems.