|The decision to hire former employees rests primarily on their former performance. The individual in question was one of your better employees, and that should tip the hiring scales in his direction.|
There are several advantages associated with rehiring him. First, he is a proven solid performer for your company. There will be no significant orientation or training costs associated with bringing him back on board, and his presence will help your current staffing shortage.
There are also some subtle advantages associated with rehiring him. For example, it will show that the corporate culture is not vindictive or mean-spirited. Some corporate cultures are premised on the belief that if an employee quits, he or she is a traitor and must be banished forever. Rather than helping the staffing situation, that type of culture exacerbates it.
Another advantage is that the returning employee is likely to be a good internal emissary for your company, since he now knows how much better it is to be working here than elsewhere. Some might argue that if he quit once, he is likely to quit again. However, others could just as compellingly argue that he has learned his lesson. Time will tell, but only if you give it an opportunity to do so.