If you think about it it is quite odd to give free labour to a company because you have shares (or some derivative of shares) in that company AND you are working for them.
Because you may also have lots of shares in companies in an aggregate fund (e.g. in a a pension) but you aren't working for free for those companies.
However people do get caught up in the emotional 'but I own a bit of it', and I think companies exploit this.
Yeah, the golden handcuffs really did shackle me emotionally. I couldn't part with the extra money to pay for the shares, even though I really wanted to leave the company much sooner. So I stayed since that was the only way I'd be able to keep the shares.
While employees may irrationally put in too much effort because of their perceived ownership value, the comparison to slivers of ownership of publicly-traded companies.
One person can make a difference in the value of a 20-person company, and if that person has a 1% stake in the company it can be rational to work longer hours to make that happen.
On the other hand, there is very little that a shareholder of a public company can do to materially affect the bottom line of that company. And as the owner of perhaps .000001% of that company, that person would see very little financial benefit from such effots.
Because you may also have lots of shares in companies in an aggregate fund (e.g. in a a pension) but you aren't working for free for those companies.
However people do get caught up in the emotional 'but I own a bit of it', and I think companies exploit this.