I didn't read this thread before.
PPC is one of the most important topics in Eco AS. Atleast one question is compulsory from this topic and it's not much difficult either. Go through the link. Great stuff.
Then, there is Markets and their system. In simple words, demand and supply. If yuh have done IGCSE's this stuff is simply revision.
Then comes Inflation, BOP, exchange rates and the policies govt uses to achieve its objectives. Fiscal, monetary and supply-side policies. Inflation and Balance of Payments areb too detailed in AS so yes, yuh need to be thorough with it.
Then comes market failure. It includes all the reasons why and how market fails and how and all the things related to demerit, merit and public goods.
Lastly, there are costs. Short-term. Long-term. Marginal. and all the graphs related in each situation - When there's a monopoly, oligopoly or intense competiton. Barriers to entry/exit.etc. So yeah. This was one general view of my AS level. =/
