The multi-employer pension plan model actually exists today in Canada, but to join it you have to be affiliated with the other employers. For example, in the construction industry, you'll have a number of stand-alone companies that are able to join an MEPP, because they all happen to be part of that particular industry. But if a company that makes auto parts wants to join in with a company that is a wholesaler of food, today they cannot join. There are limitations in the law, which won't allow them to join together in a common plan.
The DC-MEPP is a plan in which individuals have their own account balance, so the plan is always fully funded. It's whatever they happen to have in their account balance that they, and possibly their employer, have put in. If they leave that company, it's portable in the sense that they can just leave their money there and move from company to company. It's simple. It's meant to drive down costs by taking advantage of the economies of scale inherent in the business. And there's really no risk to the employers who participate in that multi-employer plan.