An analysis done for the Wall Street Journal by real estate portal Zillow.com, shows the median down payment in nine major U.S. cities rose to 22% in 2010 on properties purchased with conventional mortgages. Banks favor higher down payments today because it reduces the chances of delinquencies. Median down payments were at about 20% in 1990, then the payments declined in the nine cities Zillow looked at: Chicago, Stockton, Las Vegas, Miami, Phoenix, San Diego, San Francisco and Tampa. The drop went as far as 4% in 4th quarter 2006, and in some places close to zero. Experts say these are the markets where more home buyers are under water. A 2009 study by the Federal Reserve Bank of St Louis shows that buyers with smaller down payments are more likely to default in unfavorable economic situations. A contributing cause of the 2008 sub-prime mortgage crisis was the very low down payments. Federal Deposit Insurance Corporation chairwoman Sheila Bair, says she supports minimum 20% down payments....