The second economic boom in the history of Ribeirão Preto occurred after the oil crisis (1973 and 1979) of the 1970s. The increase in the oil price obliged Brazil to look for alternative means of fueling and the solution found was the alcohol fuel program, or "Pro-Álcool" as it is called. Pró-Álcool led to the development of a technology which allows the use of ethanol (sugarcane alcohol) either as automotive fuel or as a gasoline additive. The latter improves performance and substitutes lead thus decreasing polluting emissions. Due to the Pró-Álcool program, farmers from the region of Ribeirão Preto were encouraged by government subsidies to grow sugarcane. The high productivity of the land around Ribeirão Preto rapidly placed the region as the largest alcohol and sugar producer of the world, being responsible for 30 percent of Brazil's sugarcane alcohol fuel.