More people quit their jobs in December than anytime in the past 16 years, the Labor Department reported Tuesday.

In the month, 3.259 million workers voluntarily quit their jobs — an encouraging number. Economists generally see higher quits as a sign that workers have confidence that jobs are plentiful enough that they'll find another position easily.

The last time that many workers quit was in January 2001, during the dotcom bubble.

Tuesday's numbers, which are adjusted for seasonal fluctuations, come from the Department of Labor's Job Openings and Labor Turnover Survey. JOLTS, as it's known, is released on a one-month lag from the payroll jobs report. But investors and Federal Reserve officials value it because it contains information about gross hiring and firing that aren't available anywhere else.

The other details of the report showed steady progress in the labor market. Overall hiring and job creation weren't much changed on the month. At this point in the recovery, there are just 1.1 unemployed workers for each advertised job opening, a ratio lower than even during the housing bubble. During the worst days of the recession, there were more than six unemployed workers for each opening.

The January jobs report, based on a separate survey and counting net job growth, showed 200,000 new jobs added in the month, a very strong pace given the length of the recovery.