Why is that is there any verifiable statistics to back this up?
There is very little statutory protection for employees in the USA so the actual cost of firing some one isn't that high.
There is very little statutory protection for employees in the USA so the actual cost of firing some one isn't that high.
So think about it from Google's point of view. You take a risk, hire a programmer that doesn't pan out. You fire him after 6 months. That's 6 months of salary and benefits. 6 months of bad code sitting in your code base. 6 months of lower productivity for whoever was on that person's team. And probably another 6 months after that of clean up either ripping out bad code, or worse, leaving passable code that turns bad at a later date causing even more work.
It is better to just take no action on a potentially good candidate and let them try again in a year than it is to take even a small risk on someone who might cause things to snowball.
The legal cost is low, but the social cost of a workplace where people often get fired is high.