The government reported a 4.5% unemployment rate, but here's the realistic number

The unemployment rate fell to 4.5 percent in March, according to the Labor Department. But relying on that one headline number as an indicator for the economy as a whole ignores important information just below the surface.

Each month on "Jobs Friday," the Bureau of Labor Statistics releases a ton of economic data, each point providing its own perspective on the employment situation. Economists look past the official unemployment rate — that 4.5 percent figure, also known as the "U-3" — to other measures of jobs in this country.

One of those measures is the U-6 rate, which has a broader definition than the U-3 rate. In March, that figure fell three-tenths of a point to 8.9 percent.

The official unemployment rate is defined as "total unemployed, as a percent of the civilian labor force," but doesn't include a number of employment situations in which workers may find themselves. The U-6 rate is defined as all unemployed, "plus all persons marginally attached to the labor force, plus total employed part time for economic reasons, as a percent of the civilian labor force."

In other words: the unemployed, the underemployed and the discouraged.

The U-3 rate has in the past few months returned to the prerecession levels that economists consider full employment. The U-6 has seen significant improvement in that time, but still remains higher than before the recession.

Nonfarm payrolls increased by only 98,000 jobs in March, falling badly short of consensus estimates of 180,000. Expectations were running high after private payroll firm ADP reported robust gains on Wednesday.

A falling unemployment rate isn't always a good thing. The official unemployment rate only measures people who are in the workforce: actually employed or seeking employment.

That's one reason economists rely on the labor force participation rate, which measures the portion of the population that's either employed or looking for work. The participation rate has fallen significantly since its high around the year 2000, likely due to demographic shifts like baby boomers retiring. But those demographic shifts don't account for all of the change, which has led some economists to think it's more to do with fundamental shifts in the economy.

In March, the labor force participation rate remained unchanged at 63 percent.

Another measure of employment used by economists is the ratio of vacancies posted (v) to the number of unemployed persons (u). This v/u ratio measures labor tightness: A rising indicator means more businesses are looking to fill positions relative to the number of job seekers.

The v/u ratio had been rising since the end of the recession, but has slowed in recent months. It stood at 0.74 in January, the most recent figure available.

As more Americans find work and the labor market tightens, you can expect wages to rise because of the competition among employers to attract the remaining qualified job candidates. In recent months, wages have again gained ground after years of tepid growth. But some economists have worried that many of the jobs being added are low-wage, low-skill positions.

In March, average hourly wages were up to $26.14. Average weekly wages rose to $896.60.

ADP's report came as a relief: The warm weather in February had economists worried that industries likes construction had added all they would and the normal seasonal adjustment techniques would be off later in the year.

Overall construction spending was up about 3 percent in February over the month last year, according to the Census.