I am doing a regression that involves many countries. One independent variable is revenues of sampled companies in each country. But the data I have use the reference countries' currencies (so I have multiple currencies).
The model requires me to scale the independent variables such as revenues using lagged assets (e.g., revenue(t) in Yen divided by assets(t-1) in Yen).
So the question is, do I need to have a uniform currency say US\$, or won't the outcomes change even if the currencies are different, as long as the currencies used are the same in each company?