Answer

"Surveillance of national trade policies is a fundamentally important activity running throughout the work of the WTO. At the centre of this work is the Trade Policy Review Mechanism (TPRM). All WTO members are reviewed, the frequency of each country’s review varying according to its share of world trade." WTO website.  Go to the following: World Trade Organization, Trade Policy Reviews. 

You may want to consult the NYU guide to WTO/GATT Research which provides additional research guide links.