Obviously in terms of the overall contents they are not the same - even eventually. Alcohol contents can be the same but the rest of the drink can not be discarded from the equation. For example, my body react poorly to high amounts of sugar, so drinking a sugary cocktail is vastly different from a shot of tequila. Beer instantly makes me feel bloated, so if I drink 2 pints of beer to match a glass of scotch, I will feel slow and foggy, not upbeat and sociable.

Like I said, your not drinking enough.