Expect an increase in folks wasting their lives away. Drugs are pleasurable, including alcohol. Tokers always assure themselves that they can't be noticed, because the body doesn't give off a reek like alcohol does. Can you smell cocaine on someone? The "slow-but-safe" driving thing is as as old as the hills, put out as a common argument - judgment is impaired, plain and simple. Tokers have no problem aiming for the interstates. It's all giggles by then, after all. Escapes from reality - pleasurable.
You'll dig hard to find information, but during prohibition, the day-to-day crimes - the domestic beatings, people losing jobs because of being unable to show up, petty thefts etc. went down.
There is a qualitative difference between downing enough alcohol, and puffing to change the mind. Puffing is far more convenient, for one. Same as snorting a line.
A reading about the effects of opium on 19th century China can be instructive.
I'm well aware of the crime happening because of drug laws. It rips cities apart. Murder, mayhem, etc. But as long as they are illegal, it's important to understand that each puff, each line snorted, has a trail of murder, beatings, rape, extortion, whole nations terrorized behind it. There is nothing about it that is "victimless".
As one imbibes, the pleasure one gets from drug use comes to you through the horror of millions as it stands today. Make no mistake about that. "Blood" diamonds that are talked about don't come close by a long shot.