During 2007, the U.S. economy was hit by a price shock when the price of oil increased from around $60 per barrel to around $130 per barrel by June 2008. While inflation increased during the fall of 2007 (from around 2.5% to 4.0%), unemployment did not change significantly (it even increased slightly). Explain the relationship between inflation and unemployment in 2007 using the modern Phillips curve concept.