Answer: Future favors
Step-by-step explanation:
As much as money is currency in developing countries, so also are future favors, albeit, to a lesser extent. Sometimes, in order to get something done, people promise to pay in kind in future when the party that is to help them in the present will need help.
This can result in the exchange of privileges over years and even generations as promises made have to be fulfilled. Whilst this can foster ties between families over generations, it can also lead to the placing of an unnecessary burden on future generations.