I have a dataset that contains a few hundred transactions from a three suppliers operating in 100+ countries over a three year period.
We've found that the country of sales is not a significant factor in the prices achieved (the products are more or less global commodities). All of the prices have declined significantly over time. Any one day can have multiple transactions at different prices from the same supplier (i.e. in different countries).
I would like to test whether there is a statistically significant difference in the prices charged by the different suppliers.
The data look something like this:
Country X 1/1/2010 $200 Supplier A Country Y 1/1/2010 $209 Supplier A Country Z 1/1/2010 $187 Supplier A Country A 1/1/2010 $200 Supplier B Country X 1/2/2010 $188 Supplier B
Any ideas on how to do this?.....