Things like economic costs (such as pension accruals) and social costs (friendship ties with co-workers) would be costs of losing organizational membership. But an individual doesn't see the positive costs as enough to stay with an organization they must also take into account the availability of alternatives (such as another organization), disrupt personal relationships, and other "side bets" that would be incurred from leaving their organization. The problem with this is that these "side bets" don't occur at once but that they "accumulate with age and tenure".