If you ride a bicycle and you choose to wear a helmet, there may be a benefit to you in you crash.
However if you choose not to wear a helmet, the overall health outcome for you is positive and you are saving the taxpayer money. That’s because the health benefits of riding a bicycle outweigh all the risks by a large factor. For example an article in the British Medical Journal compares the health benefit of riding public share bikes with the risks and finds a large net benefit. The British Medical Association publication “Cycling: Towards Health and Safety”. Oxford University Press; 1992. found that “in spite of the hostile environment in which most cyclists currently ride, the benefits in terms of health promotion and longevity far outweigh the loss of life years in injury on the roads.” Bicycling: Health Risk or Benefit? reported “Benefit to risk ratios ranged between 9 to 1 and 96 to 1.” in a range of studies. Note that helmet wearing rates are far below Australia’s for these studies.
In “Physical Activity in Australia: A Snapshot, 2007-08“, the Australian Bureau of Statistics estimated that the direct health care costs due to physical inactivity in Australia were almost $1.5 billion in 2006-07.
Cycling in the Netherlands, where helmet wearing is rare, saves the health budget 3% of GDP, see Dutch Cycling: Quantifying the Health and Related Economic Benefits.
So when you see someone riding a bicycle without a helmet, you can be glad they are saving you money. By the way, the health benefits of riding are approximately 50% of the total benefits (the other benefits include congestion, pollution etc).
Next time somebody tells you that you should pay your own health costs if you ride without a helmet, ask whether people who don’t ride a bicycle should pay a lot more than that towards the higher health costs due to inactivity.