S n as 17. TECHNOLOGICAL CHANGE AND UNEMPLOYMENT What are some examples of technological changes that have caused un- employment? And what are some examples of new technologies that have created jobs? How do you think you might measure the net impact of technological change on overall employment and GDP in the United States? 18. SHIFTS IN THE PPF Terrorist attacks foster instability and may affect productivity over the short and long term. Do you think the September 11, 2001, terrorist attacks on the World Trade Center and the Pentagon affected short- or long-term produc- tivity in the United States? Explain your response and show any movements in the PPF. vs d- ill -ill