http://www.nytimes.com/2016/10/26/business/economy/if-immigr...
No one would walk miles through the Arizona desert if it were easy to do things legitimately - the only people sneaking around would be actual criminals.
And of course this one is a classic:
http://johnhcochrane.blogspot.com/2014/06/the-optimal-number...
You start enforcing it for the most egregious cases and others get a little more hesitant to break the law. Then you do it again and more back off. At some point, you reach a happy medium where there's "enough" enforcement that egregious cases are rare and punished heavily while the rest aren't worth punishing.
Yes, just like speeding.
Greece, however is a good point: if you make your economy bad enough, no one will want to go there. This worked for the US during the recent recession.
Hell, I'd help the law with tips myself if it meant companies would be forced to increase wages as the market forces shake to accommodate decreased supply.
This idea would work in a world where both malevolence and all kinds of errors do not exist. Ours is, unfortunately, different.