Legal and privacy experts warn access can be used against workers.
More than a third of employees are happy to grant their bosses access to their Facebook pages
A global survey of 10,000 people by PwC, done to look at how the workforce would evolve in the next eight years, found more than 30 per cent of participants would willingly give their employers access to personal data such as social media profiles to enable them to better understand what made them tick.
PwC partner and HR transformation specialist Debbie Francis said there appeared to be a new way of thinking among the younger generation, who took a view that employers should be using good sources of data on the workforce, rather than seeing it as a muck-raking expedition.
"Granting data access to employers will give them the ability to better anticipate and measure performance and employee retention, and could extend to the monitoring of employees' health to reduce sick leave."
Ms Francis said that while handing over access to social media profiles relied on a high level of trust between the two parties, it was also down to the employer to demonstrate obvious incentives for doing so.
But Dundas Street Employment Law partner Susan Hornsby-Geluk said employers mainly used social media to help discipline a current employee or trawled social media sites to vet a possible candidate.
"It would be fairly creative for employers to take a more sort of pro-active approach of screening Facebook profiles to see how happy their employees are. To be frank, I'm not not aware of many employers doing that - you would need to have a lot of time and resources."
Employers had in the past used social media to prove a staff member had taken sick leave when there was evidence on Facebook to suggest they were not ill.
Ms Hornsby-Geluk had also been involved in a case when an employee had been disciplined and then dismissed for posting derogatory comments about their employer.
Council for Civil Liberties spokesman Thomas Beagle believed that giving employers access to social media was not appropriate and blurred the line between personal and private life.
"Your personal life contains all sorts of things which is no business of your employer - your sexuality, some of your personal history."
Of more concern to him was that staff would also be giving away a lot of their friends' privacy as well.
Mr Beagle said employers could use their access to social media profiles to try to find out if a staff member was looking for a new job.
Vital to update online profiles
More than half of job-seeking Kiwis update their CVs on a regular basis - but are slacker at changing their social media profiles.
Employers are increasingly turning to the internet to check on candidates, and Hays Recruitment managing director Jason Walker said it was vital employees took a dual approach to job-hunting.
A Hays Recruitment survey of more than 770 New Zealanders found only 21 per cent kept their professional social media profile, such as on LinkedIn or Facebook, updated.
Mr Walker said neglecting to update online profiles could prove detrimental, and also warned candidates to make sure their Facebook settings were secure so employers could view only what they wanted them to.
"LinkedIn is useful, but you need to maintain a traditional CV since it is also often your first introduction to a potential employer, who will then turn to social media to find out more.
"Anything you put online either has the potential to promote you as a great employee or provide you with negative branding, so ultimately you are branding yourself online with whatever you post on there."