Abstract
One of the notable features of increasing unemployment is that the net employment declines at firms as middle-aged and older employees increase. Our empirical study confirms this fact, even controlling for endoseneity and selection biases. Young workers are more likely to face difficulty in finding full-time jobs at aging firms. Until the mid 1990s, senior workers could find new employment opportunities through direct transfer between firmes. However, a huge increase in displaced senior workers occurred after the financial crisis of 1998. They also face difficulty in job finding without personal networks and firm-to-firm relationships.