Gresham's law the creditor must accept such money at face value. Nobel Prize winner Robert Mundell believes that Gresham's Law could be more accurately rendered, taking care of the reverse, if it were expressed as "Bad money drives out good "if they exchange for the same price"." The reverse of Gresham's Law, that good money drives out bad money whenever the bad money becomes nearly worthless, has been named "Thiers' law" by economist Peter Bernholz in honor of French politician and historian Adolphe Thiers. "Thiers' Law will only operate later [in the inflation] when the increase of the new flexible exchange rate
Good Girl Gone Bad Pitchfork Media described the opening lyrics of the song as inspired by "puerile psuedoporn". The album concludes with the title track "Good Girl Gone Bad", which is played with an acoustic guitar and click tracks. Released as the lead single from "Good Girl Gone Bad", "Umbrella" was sent to contemporary hit, rhythmic and urban radio in the US on April 24, 2007. The song received acclaim from music critics, who praised its production, vocals and the collaboration between Rihanna and Jay Z. "Umbrella" reached number one in more than seventeen countries worldwide, including on the UK Singles Chart and the