"Taxing the Rich" Won't Help Pennsylvania

The Wall Street Journal has an article today on how Maryland's higher taxes on "the rich" drove millionaires to move to other states.  Last week, the NY Post had a good op-ed from Tom Golisano, who was taking his income from high-tax and spend New York to Florida, which has no income tax.

There should definitely be a lesson for Pennsylvania in all of this, but some groups continue to call for higher taxes on "the rich."  Yet even the biggest advocates of statism acknowledge that when you tax something, you get less of it - hence proposed "sin taxes" on smoking, carbon emissions, and soda.

What do you get less of when you increase taxes on income?  Or when you increase taxes on businesses?