Nearly half of the houses for sale in the U.S. are listed for less than what the seller originally asked for, with the average list price declining 7.1% in 26 U.S. markets, according to a survey released by ZipRealty. The Emeryville, Calif.-based Internet real estate brokerage said that in August, 47% of houses for sale had a least one listing price reduction since first going on the market, up 3.26% from July’s level. ZipRealty tracks data in 26 major housing markets. On average, home sellers are reducing prices twice to garner enough interest from prospective buyers.