I can talk to you about my experience in Quebec with community group employees whose salaries were in the $30,000 to $35,000 range, and to whom we offered a multi-employer plan. I was struck by the fact that these people, who arrived at the meeting feeling that because of the poor performance of public plans, they did not have the means to contribute to a plan, had changed their opinion by the end of the meeting. Rather, they said that they could not afford not to contribute to their retirement. The fact that their employer would also be contributing made the plan more attractive to them.
In my opinion, if employers do not have to contribute to the plan, the employees will not be inclined to do so either. In countries where automatic participation mechanisms have been put in place, employers' contributions in many cases completed employees' contributions, and this is why the participation rate was high.