The Brazilian economy was generally not affected by the mensalão scandal, which related to vote buying in the Brazilian Congress. In early 2006, however, Palocci had to resign as finance minister due to his involvement in an abuse of power scandal. Lula then appointed Guido Mantega, a member of the PT and an economist by profession, as finance minister. Mantega, a former Marxist who had written a PhD thesis (in Sociology) on the history of economic ideas in Brazil from a left-wing viewpoint, was known for his criticism of high interest rates, something he claimed satisfied banking interests. Mantega was also supportive of a higher level of employment by the state. Not long after the start of his second term, Lula's government announced the Growth Acceleration Program ("Programa de Aceleração de Crescimento", PAC), an investment program to solve many of the problems that prevented the Brazilian economy from expanding more rapidly. The measures included investment in the creation and repair of roads and railways, simplification and reduction of taxation, and modernization of the country's energy production to avoid further shortages. The money pledged to be spent on this program was considered to be around R$ 500 billion (more than 250 billion dollars) over four years. Prior to taking office, Lula had been a critic of privatization. In his government, however, his administration created public-private partnership concessions for seven federal roadways.