In 'What to Watch on Wall Street' for the week of December 28, it's another short week as we head into the new year. But expect to see some key economic reports. We begin the week with the Dallas Fed manufacturing survey, followed by the S&P case-shiller home price index and consumer confidence on Tuesday. Midweek, we get pending home sales and the weekly oil inventory data. Jobless claims and the Chicago PMI will be released on Thursday, then markets are closed on New Year's Day. Here's why investors will be watching the pending home sales index. It's one of the most important indicators of housing activity, specifically of existing home sales. Based on the demand for housing, investors will get a better sense of how the economy is doing. TheStreet's U-Jin Lee reports from Wall Street.