Seventeen percent of U.S. households — 20 million homes — have already ditched their home landlines, relying instead on mobile phones, Nielsen reported.

These “wireless substitutors” tend to live in smaller households with just one or two residents and have lower income-levels — 59% have household incomes of $40,000 or less.  A significant number moved (31%) or changed jobs (22%) just before discontinuing their landline service.

“In a tightening economy every dollar counts, and consumers are more and more comfortable with the idea of ditching their landline connection,” Alison LeBreton, vice president of client services, Nielsen Mobile, noted.

The percentage of wireless-only households has grown steadily since 2003, when just 4.2% of U.S. homes had cut their landline service.

Still, Nielsen’s research shows that wireless substitution doesn’t work for everyone.  Ten percent of current landline users experimented with cord-cutting at one point, but eventually reinstated landline service.

View the full press release.

Read the white paper, “Call My Cell: Wireless Substitution in the United States.”

Explore coverage of Nielsen’s findings in The New York Times, the Los Angeles Times, Adweek, MediaPost, Wireless Week, and on CNET.com.