Millennials have been labelled lazy and unproductive but a new report suggests the opposite may be true.

Those who were 18-34 in 2015, who will make up a third of the global workforce by 2020, expect to work longer hours and retire much later than previous generations, according to Manpower's Millennial Careers: 2020 Vision.

The working week

Results from more than 19,000 millennials in 25 countries suggest that the traditional 40-hour week is a thing of the past – almost three quarters of young people are working more than 40 hours a week.

Millennials hours worked per week

Nearly a quarter work more than 50, with young Indians working the longest -- 52 hours. Millennials in Mexico, China and Singapore are working 48 hours a week. A quarter globally had two or more jobs.

In it for the long run

More than a quarter expect to be working past the age of 70. 12% believe they will work until the day they die.

When do millennials expect to retire?

Career waves

The traditional “career ladder” of previous generations is being replaced by “career waves”, according to the report.

Millennials don’t expect to stay in the same job for many years, instead they understand the need for continuous skill development and are prepared to change jobs throughout their careers.

With the expectation of working into old age, 84% of millennials are planning to take a career break at some point – this time out could be to care for relatives or children, ‘me time’ to travel and pursue life dreams, or to return to education and gain new skills.

The report urges employers to take note of these changes in career expectations in order to take advantage of this large and growing segment of the global workforce.