ln(log) of energy consumption in a econometric analysis i'm applying a panel data analysis. I
 have four variables; real GDP, trade openness, energy price and energy consumption. I took ln (log)of trade openness,real GDP and energy price. but i cannot decide whether ln(log) of energy consumption should be taken or not. please inform me on this. Thank you 

Note: Kg of oil equivalent per capita is used to measure energy consumption.

EN= energy consumption

Y=Economic growth

T= trade openness

EP=energy price

W= country fixed effect
EN=f(Y,T,EP,W)





Thank  you.
Prior to any trasnformation:


Energy consumption is a per capita variable, specifically "Kgr per capita"
Real GDP is a per capita variable
Trade Openness is a per capita variable
Energy price is a unit price of "crude oil"


I see two problems: Is "Energy Price" the "price per Kgr" -because usually oil prices are not quoted per Kilogram. But it should expressed here "per Kgr" so as to stand for the price of the dependent variable.

If it does, it is only natural to consider the logarithms of the variables, dependent variable included.

But one more thing that needs clarification is what $Y$ stands for. The authors write "$Y$(economic growth)". If this is the case then for this variable you don't just take the logarithm of real GDP but the first-difference of the logarithm  (which approximates the rate of growth).