When studying history, asking questions and checking other sources will improve one's perspective. what other awareness is necessary? to realize all writers and reporters have some bias of culture, geography, economics, or politics. to understand all perspectives are always correct. to acknowledge primary documents are without bias. to understand the longer a document is, the more accurate it is.

when a country suffers, for example, a drought period, the market product is affected for a low offer, in this case, potatoes; the government has to tax to the households, which have to give more money for the potatoes which they consume, that situation make them consume substitute goods even through loans, it could increase the financial market movement and the inflationary phenomena, the business has to increase salaries in order to the employees could buy a more expensive food (potatoes) and in order to inflation tha business had to buy expensive supplies in the factor market, while the rest of the world have to gain more money to consume the same amount of potatoes.