I have a problem with my co-author, we do not agree on the inerpretation of the regression coeffcients. In our regression (part of a more complicated model, which does not matter here) we defined the dependent variable as log difference, that is, ln(Gt) - ln(Gt-1), where G are local investment. The most relevant independent variable is in level (St, surcharge of a tax). We are struggling with the interpretation of the regression coefficient, beta, on St. In my opinion, an increase in St of one unit leads t a beta percentage points increase in G; while he interprets it in percentage terms.
Could help us?