A wave of foreclosures and a glut of unsold homes pushed U.S. housing prices down in March.

Tuesday's report from the closely-watched Case-Shiller index of property values in 20 U.S. cities was 3.6 percent below the same month a year earlier.

High unemployment means many people lack the income needed to buy a home, while others may be worried they may not keep their jobs and do not want to take on major new debts.

Banks have also tightened lending standards, meaning fewer people can qualify for mortgage loans to buy homes.

A separate study by private research group, the Institute for Supply Management, showed business activity growing more slowly in May in the U.S. Midwest.

The downbeat reports and high gasoline prices are among the reasons U.S. consumers grew more pessimistic in May as U.S. consumer confidence fell to a six-month low.

Economists watch consumer confidence for clues about the consumer spending that drives most U.S. economic activity.