Final answer:
Benefits managers in Canada face the challenge of how to sustainably fund promised levels of benefits to an increasing elderly population with fewer workers supporting the system.
Step-by-step explanation:
The biggest issue facing benefits managers in Canada today is how to pay promised levels of benefits to the elderly, especially in the face of a demographic shift with a growing proportion of elderly and a shrinking base of workers. This issue is compounded by the need for significant national policy changes and encompasses concerns around national medical insurance and welfare benefits. Moreover, potential issues arise from the debate over the government's role in providing welfare, as well as the challenges related to union formation and the impact of such dynamics on Canadian businesses and their benefits policies.