Just to add a little more (slightly off topic but I think relevant).
There is an acronym used in industry safety management titled "ALARP", which stands for "As Low As Reasonably Practicable".
This is basically a mindset or process which looks at possible accidents and asks the simple question: "Have I made the risk of injury or damage as low as reasonably possible"
What this means is that if a company has an accident and someone is injured or died then come the inquest, if they have done everything reasonable to minimise the risk of that accident then the CEO is not likely to go to jail.
Clearly the word "Practicable" and "Reasonable" are very dependant on the individual company / person. Using BP as an example, its seems (allegedly) that they could have done more to protect the drilling platform in the USA that blew up last year and the US Government is hauling them over the coals for it.
I don't expect parents to be thinking about an inquest, but more what their family would think if the worst would happen. So if my child were have his spine crushed during an accident at some traffic lights when another driver jumped the lights and drove into the side of the car, would my family think I did all that was reasonable to minimise the likelihood of that injury. If my 4 year old is ONLY in a booster seat and I have a spare £80 in the bank which could have been better spent on a new car seat rather than on saving up for a new LCD TV, then the answer would likely be "NO" - because mitigating injury to my child is more important than getting a new TV!
If you can afford a big 4x4 Volvo, then you can likely afford £80 without too much difficulty. Would it be reasonable to sell the Volvo and buy the most modern Volvo with the best safety standards for £50,000, No, that is not a practicable thing for most people. It is all about a sensible approach to the decision.
"My kid doesn't fit the cheap seat we got him so I took the back off" - is not a reasonable and sensible decision, if you have £80 in the bank - it is not "ALARP". However, if you are unemployed and struggling to pay the bills, it is wholly reasonable and is "ALARP".
Like I say, this is an industry process and not mine. But we should all be able to justify our decisions based upon having thought about all the factors.