India has surpassed Japan to become the world's fourth-largest economy, according to calculations in the Indian government's end-of-year economic review. On current trends, India is expected to overtake Germany to become the world's third-largest economy within the next three years, the review said. How big is India's economy? The review said India's gross domestic product has already reached about $4.18 trillion (€3.55 trillion), and is projected to reach $7.3 trillion by 2030. On current trend...