Every Monday, The Takeaway looks at the big news stories from the week ahead. Christmas retail numbers and post-Christmas sales are expected to be stronger this year than in 2011. Heading into a presidential election year, voters will be looking to see how much the economy has improved. And the U.S. is not the only country that might see a shakeup in elected officials. Both China and Russia are likely to makes changes in leadership in the new year, as are a number of European countries. Charlie Herman, business and economics editor for WNYC and The Takeaway, and Marcus Mabry, editor-at-large of The International Herald Tribune, look ahead at the big stories of the week.