The issue is that hiring new grads only pays off if they stay for at least 3-4 years in my guestimation. If the new grad leaves before that timeframe they were

The issue is that hiring new grads only pays off if they stay for at least 3-4 years in my guestimation. If the new grad leaves before that timeframe they were most likely a net negative on the project/company and consumed more resources than they produced. Most new grads are desperate to get a job so they will take anything just to get experience so they can leave a year or two later for a company which they prefer, so unless you are google or facebook you are probably going to have issues retaining newgrads.