I think the safety argument is somewhat more complex
Correct, that is my point.
There is no study which in anyway tries to quantify these differences, hence argument is based on 'logic' rather than statistics
I disagree about it being based on "logic". Quite the opposite, the statements which I dispute in AOPA's writeup as quoted by M. Cross are based on fallacy, as is my Spanish example.
I suspect what they did was pull some fatality figures off the respective national investigation agencies' publications / websites, without regard to their different fields of competence and methodologies. For example, the BEA investigates, and includes in its statistics almost every kind of aerial activity such as microlight and paragliding (enormously popular in France) while the AAIB, to my knowledge, doesn't. As you can appreciate, that results in two different populations (in the statistical sense) that you are trying to compare across.
Furthermore, even if the validity of those comparisons could be determined (which is possible, it just takes a bit of work) and there was found to be a statistically significant difference (which is a further half an hour of a statistician's time) there is the much hairier job of a) establishing correlation, and b) establishing causality between any such hypothetical difference and the fact of having or not having an IMCR, either as opposed to an IR, or as opposed to vanilla VFR privileges.
The people seeking to retain the IMCr are, in general, coming from a safety vs utility perspective. In that IMCr trained pilots are clearly safer undertaking ILS approaches in IMC than people with only a PPL
I believe it has been discussed before and I do not wish to start that debate again, but from a safety point of view the pilot with only a PPL has the advantage, as he is not authorised to fly in IMC conditions and therefore has to stay on the ground, which greatly reduces your chances of becoming involved in an aviation accident, whatever the weather. But of course we understand that this is not really viable on account of the British weather, so one comes up with an arrangement that allows people to fly in more marginal weather than would otherwise be possible, thus giving an
utility advantage as you well state, but a priori reducing safety as you have now increased the exposure, purely from having another plane in the air which otherwise wouldn't be there and without regard to any other factors.
Therefore, as I have said on my previous post, you have a demonstrable economic benefit (or utility value as you call it), which personally I find a good selling point in itself as previously illustrated.
IMHO it is more objective to say 'the IMCr greatly increases utility with no observed decline in safety'
I agree that such a wording would be an improvement over the original version, however I would leave out the complement clause altogether.
In summary, I think AOPA's document is 'reasonable' in the context of a lobbying letter
I could not possibly comment on that point, not being very familiar with lobbying or politics in general. However, from the point of view of someone who values integrity, I could not put my signature to something I know or strongly suspect to be a lie. Mine was a general commentary on that sense.
Englishal
You have some odd views. Of course it is about safety
Methinks you have misinterpreted me. In Europe the mountain qualification allows you to fly in, land, and take off from areas which would otherwise be off-limits for fixed-wing aviation. The exercise of the privileges of such a qualification entails a very significant level of risk, even if that risk is of course lower than faced when operating into those sites in disregard of the regulations.
That leaves countries that have the qualification exposed to higher accident rates than countries which don't, all other things being the same. My point with that example was to show that it is not necessary to pull the safety card to achieve the goal at hand--indeed, to my untrained eye that looked like a rather poor move.
seeing the number of brits who try to take a fully loaded PA28 into a 7000' airport
This is off-topic, but I presume you are not talking about Europe? The only aerodromes at or above 7000ft in Europe are classed as altiports and a mountain (or site) qualification is a requirement, not merely a recommendation.