An 8.5% unemployment rate is unmistakably bad. It’s the highest rate since 1983 — a year that saw double-digit unemployment, nearly 30 commercial bank failures and more than 15% of Americans living below the poverty line.

But the real national unemployment rate is far worse than the U.S. Department of Labor’s March figure, announced today, shows. That’s because the official rate doesn’t include the 3.7 million-plus people who are reluctantly working only part time because of the poor labor market. And it doesn’t include the workers who have given up scouring want ads for seemingly nonexistent jobs.

When those folks are added to the numbers, the unemployment rate rises to 15.6%. In March 2008, that number was 9.3%. The Bureau of Labor Statistics began tracking this alternative measure (.pdf file) in 1995.

“The situation out there is very grim,” says Heather Boushey, a senior economist at the Center for American Progress, a left-leaning think tank. “We have seen the mounting of job losses faster than any point since World War II. I have never seen anything escalate this bad.” Here’s another way to look at the unemployment figures: More than 5 million people have lost their jobs since the start of the recession in December 2007. And more than 13 million people are unemployed. That’s the highest number the U.S. has seen since it began tracking unemployment after World War II. For every job out there, more than four people are competing for it, says Boushey. Some unemployed workers have become so frustrated by the difficulty of landing a job that they’re exiting the labor market altogether. Prior recessions saw a spike in the number of women choosing to be stay-at-home moms rather than continue to compete for work. This recession has seen a large spike in the number of laid-off men opting to become stay-at-home dads — or at least stay at home.

Once people stop looking for work, they’re no longer entitled to unemployment benefits.

This is not news to those who are paying attention.