Excerpt: No matter how familiar we are with the 401(k) system, we must never take it for granted. It is a uniquely American creation ? innovative, flexible, driven by a unique private-sector partnership operating in a framework of sound policy decisions, and well-suited to the needs of an evolving American workforce. It enables workers of ordinary means to save, to share in the wealth and productivity of American business, and to enjoy a more secure retirement when their careers are complete. Its success is evident in the $8 trillion ? half of Americans' retirement assets ? that can largely be attributed to savings in defined contribution plans.