USPS begins partial slowdown this week in cost-cutting measure

The United States Postal Service this week began its planned slowdown of mail delivery throughout the United States, which postal leaders hope will help keep costs down for the famously expensive federal agency.

Nearly half of all first-class mail pieces will see a decline from a three-day U.S. delivery guarantee to a five-day guarantee. Locally delivered mail will still retain a guaranteed two-day delivery. 

Mail delivery "will be slower than in the 1970s," one expert told CBS News. 

The measure is one among several being taken to head off what is projected to be a $160 billion loss for the agency over the next decade.