Firing in IT companies | yearly lay off is common in IT | Seniors are targeted to reduce cost

Most of the IT companies lay off employee on the basis of performance. Most of the target is on senior resource who get paid heavily. Only few survive in IT till the retirement. Thus IT comapanies pay more and fire more. 

To get survive in IT, you need to be more talented and should have skill in good technology. Obviously good guy for your manager. In IT, Salary Hike and firing the employee is on manager hands.