The document summarizes some of the key difficulties with barter systems. Specifically: 1) Lack of double coincidence of wants, meaning it was difficult to find situations where two parties both had goods the other wanted to exchange. 2) Lack of divisibility, since some goods like cows could not be easily divided to exchange for multiple smaller goods. 3) Lack of a common measure of value, since there was no standard unit to assess the relative values of different goods against each other. 4) Lack of ability to store value, as perishable goods were difficult to stockpile for future exchange or use as a store of wealth.