PPF of our country is based on potential the most efficient use of our resources, NOT their actual use. The problem is, it's unclear for me how to estimate said potential. How to know where potentiality ends and impossibility begins? Not necessarily with clean-cut distinction, a rule of thumb can be good enough too.
(An increase of productivity needs a cultural shift) Maybe we would be able to increase production by increasing participation of women in the workforce, but our culture CURRENTLY dictates that married women should NOT work. So would our PPF include increased production caused by by cultural shift? Or would we experience an increase of PPF?
(An increase of productivity needs a political shift) Maybe our production would increase if we used these sweet new technologies. But alas, we can't have them due to sanctions and it would require radical change in our current political regime in order to have possibility for sanctions being lifted. If sanctions were lifted after revolution would it mean that our PPF increased or that we got closer to it?
Maybe our production would increase if we used industrial espionage to get new technologies, but such secret operations have very high possibility of a complete failrue. Would success mean that we increased our PPF?
Maybe our production would increase if there was industrialization in our society. But our society have never been industrialized in the first place. And it would take many years and lots of efforts to industrialize it.