Hyundai and Kia admitted in early November that self-calculated estimates for gas mileage were too high, following an investigation that was prompted by the EPA. The problem affected 35 percent of 2011, 2012 and 2013 model-year vehicles sold through Oct. 31, 2012.

FORBES: Los Angeles Auto Show: Hyundai and Kia Humbly Apologize For Exaggerated MPG Figures

For now, though, it still has a few additional hurdles to overcome, namely consumer perception (the NHTSA estimates self-driving cars could reduce crashes by 80 percent) and possible WiFi interference from the whitespace spectrum freed up by the FCC.

ENGADGET

Around 70% of Brazilians own their own homes, but many of these (around 85%, Mr Paim de Andrade estimates) are self-built one room at a time, and are of low quality.

ECONOMIST: A housing boom has investors swooning

The Center for Disease Control and Prevention estimates that 85% of self-reported drunken drivers were binge drinkers.

CNN: Don't lower threshold on drunken driving

Academic estimates are that these statistical biases of self-selection (reporting is optional for the largely unregulated hedge fund industry) add 3-5 percentage points to index returns.

FORBES: Chasing the Mirage of Hedge Fund Returns

The government estimates that the percentage of non-payers among self-employed and part-time workers is over 40 percent.

FORBES: Work Begins on Reforming the National Pension

Roughly 63% of all uninsured workers are either self-employed or work for firms with fewer than 100 employees, estimates the Employee Benefit Research Institute.

FORBES: Magazine Article

Bowker estimates that over 235, 000 books and ebooks were self-published in 2012 alone.

FORBES: Why Public Libraries Matter: And How They Can Do More

Collecting each bank's estimates of its rivals' borrowing rates would help identify any over-optimistic self-assessment.

ECONOMIST: A financial benchmark that badly needs an overhaul