# Which model to use when one variable is country specific and the other is company specific?

So basically my study is on a single country with a 10 year time period. The sample is of several companies of that country. My independent variables are of two kinds, one is country-specific macroeconomic and the others are company-specific financial. The dependent variable is also company specific. I am trying to find the joint effect of the two independent variable on the dependent.

The problem here is that since the country is same, hence for a single year all the companies within the sample will have same values for the macroeconomic variables. I don't think time series will work since I am not suggesting that current period y depends on past period y. But I am also not sure whether this is a panel data as I am focusing on a single country.

Which model should I use? Should I use interaction term?

• So you have something like $y_{ij}=\beta_0 + \beta_{1i} x_i + \beta_{2j} z_j$ where $i$ indexes the country and $j$ the company ?
– user83346
Sep 27 '17 at 9:22
• No. Because the i index for Y variable does not change as the entire sample is from the same country. This means that value of x will also change only if the time period changes. Sep 27 '17 at 12:09
• Also since I wish to find the combined effect, I was wonder if an interaction term could be included or not Sep 27 '17 at 12:17
• Could you write down the formule that describes your model?
– user83346
Sep 27 '17 at 13:45