BA-loney. Your own supporting statement says people spent more, not drank more.
Prior to Prohibition, about half the states made alcohol illegal. Alcohol consumption dropped, and dropped dramatically. As soon as Prohibition went into effect, alcohol consumption rose, but to levels lower than pre-Prohibition.
Per Capita Consumption of Alcoholic Beverages (Gallons of Pure Alcohol) 1910-1929.
So, how pray tell can the gov't tell us that consumption went down, while 'speakeasy', 'Bootleggers', 'Smugglers' and home stills prospered? The gov't only had data on taxes. By extrapolating the income from tax revenues associated with various alcoholic drinks, one can compute the average consumption rate. When prohibition went into effect; liquor sales plummeted (go figure!). It did NOT go to zero, as alcohol was made available for hospitals for sterilization (and it was closely monitored there).
People began making 'Washtub' Gin, Corn Whiskey and home made Beer (which is all very easy). How do you measure this?
People spent more, and those who could drink, drank more. We also had an entire change in the drinking styles. Whiskey, Gin, Vodka used to be the drinks associated with the low-life drunks. Wine, Conac and distilled liquors were popular, with Beer running pretty much number one. When the bootleggers found that they could either smuggle a case of beer in, and get 4 people drunk; or smuggle a case of whiskey in and get 40 people drunk.
This created more potent spirits that didn't exist previously (Everclear) and created a market for a group of drinks considered very 'Low Class'.
Today, we have new 'designer' drugs coming out, that are more powerful and more addictive than their predessors. Pot today is much more powerful than the stuff we had availalble (and I ignored) while in High School. This is because one of the side effects of Prohibition is to make the product more concentrated so profit goes up, and transportation problems go down.