If financial advisors ask clients the rate of return for their rental real estate investment property, they should expect to hear a number at least 5 percentage points higher than the actual one, according to the founder of The Real Estate Whisperer Financial Planning.That's because of calculations based on "optimistic assumptions, untracked costs and the absence of formal benchmarking" among many owners, said Rich Arzaga, founder of the Monument, Colorado-based firm, in a presentation at this week's Financial Planning Association Retreat in Oak Brook, Illinois."It's where ownership bias meets the...