Remember when building stability on a job required more than five years of service? Well, Tony Sarabia’s got that covered. He’s been here for more than 20 years. Employers wanted that symbol of loyalty and employees wanted to be vested in the company’s retirement plan. Looks like that’s no longer the norm. Could switching jobs every three or four years be a better plan? Alain Cohn of the University of Chicago’s Booth School of Business breaks down the pros and cons of job hopping.