Government workers and their unions say that scrapping traditional public pensions, as Gov. Arnold Schwarzenegger proposed last week, would make it hard for the state to hire and keep qualified workers. It would rewrite the long-standing deal in which government workers trade better pay for more secure retirement, they say. Backers of the overhaul disagree, saying government workers now approach pay parity with the private sector. New 401(k)-style accounts will let workers change jobs without giving up retirement benefits, they say, encouraging a healthy rate of turnover. The reality is more complicated than either side depicts. Take the issue of...