In some cases, production costs increase so much that it makes sense not to proceed with oil field development, which in turn impacts total oil production globally.

FORBES: Outlook For Exxon Includes Growing Production Costs

"It makes no sense for us to consider this trade issue in total isolation from the real world that we live in, " he said.

CENTERFORSECURITYPOLICY: Center For Security Policy

In these circumstances, I believe it makes good political sense to keep it simple and just guarantee that no worker with personal accounts will get less in total benefits than Social Security promises today, rather than try to defend a complicated, more limited guarantee.

FORBES: A Personal Account Option For Social Security