I am currently working on a project where I want to explore how changes in a couple of currencies affects the income for my countrys exported fish. My country (Norway) sells it fish in 4 different currencies (USD, EUR, GBP and YEN), so I have made a price index involving this four currencies. For an example, a norwegian company will earn more if USD/NOK = 10 compared to if USD/NOK = 8.
My goal at the end is to compare our total income with the price index to see how changes in the currencies affects our income (in R).
I have a lot of data for many years available, including:
- Montly Price index
- Monthly income of exported fish
- Monthly quantity of exported fish
My problem is that the monthly income of the exported fish is seasonal. For an example, the income is always lower in april then in october. The reason for this, can for an example be that we sell the fish more expensive in october then april because the market is always better in october.
Because some of the changes in our income is seasonal, it will give me fake results. Does anybody know how I can fix this problem? Will the value of income/quantity fix the problem?