For a log-log model ln(Y)=β0+β1ln(X)+ϵ\ln(Y) = \beta_0 + \beta_1 \ln(X) + \epsilonln(Y)=β0+β1ln(X)+ϵ, how is the coefficient β1\beta_1β1 interpreted?
A 111 unit increase in XXX leads to a β1\beta_1β1 unit increase in YYY.
A 1%1\%1% increase in XXX leads to a β1%\beta_1\%β1% increase in YYY.
A 1%1\%1% increase in XXX leads to a β1\beta_1β1 unit increase in YYY.
A 111 unit increase in XXX leads to a β1%\beta_1\%β1% increase in YYY.