Help, I've been reading through a journal but I do not understand what the author is referring to. In the journal, he writes that

"When I regress ownership concentration on country dummies (not reported), the adjusted R2 is 0.24. This represents the maximum amount of variation in ownership concentration that can be explained by all country-level factors. Thus, although ownership concentration is influenced both by firm-level and by country-level factors, the firm-level factors seem to be the dominant influence."

What does he mean by regressing ownership concentration on country dummies- how does this work on SPSS? I have 8 different countries in the sample. Does this mean I would have to assume Country A = dummy variable 1 and all other countries = the value 0? then regress these against ownership concentration? if this is the case, I would have to perform 8 different scenarios where country B = 1, all others = 0... country C = 1, all others = 0 ... etc? It sounds a little silly to me please correct me! I'm an idiot at stats... thank you!