Florida citrus growers say that the recent crackdown on illegal immigration is increasing the market wage rates necessary to get their oranges picked. Some are turning to $100,000 to $300,000 mechanical harvesters known as "trunk, shake, and catch" pickers, which vigorously shake oranges from trees. If widely adopted, how will this substitution affect the demand for human orange pickers? What does that imply about the relative strengths of the substitution and output effects?