Zimbabwe's government admitted defeat Thursday in a fight against dizzying inflation, allowing business to be done in U.S. dollars and bank notes of neighboring countries. Zimbabwe has the world's highest official inflation, with its currency now printed in the trillions of dollars. This month, the central bank introduced a new 100 trillion Zimbabwe dollar note. The announcement by acting Finance Minister Patrick Chinamasa acknowledged the black market practices that have been a reality for months because of Zimbabwe's economic meltdown. [...] Zimbabwe has been nearly paralyzed by the crisis precipitated by disputed presidential elections last year. Politicians agreed to a coalition government in September but for months have been unable to agree how to share Cabinet posts. The impasse has stranded Zimbabweans in a prolonged economic crisis, with hospitals, schools and sanitation infrastructure left to collapse. The U.N. food program said Thursday that 7 million Zimbabweans -- 80 percent of the population by some estimates -- need food aid.