We obtain tradable PPP if the aggregate price indices consist only of tradable goods. If aggregate price indices consist of non-tradable goods, we will obtain non-tradable PPP. Examples of non-tradable goods are haircut services, taxi rides, rent, school fees, etc. Non-tradable goods are not traded and are not affected by foreign prices. Haircut service is non-negotiable as it is very expensive to bring in hairdressers from abroad, so people turn to local shops. On the other hand, agricultural products are transportable but governments often do not allow free importation, so they are artificially transported.