"Due to varying definitions of "billion", etc, and increasing globalisation, eventually one standard definition had to be agreed upon, to avoid confusion and misinterpretation."
"That was surely an admirable step to take. When was it taken, and who agreed upon this /standard/ definition?"
Well, I honestly don't know. When I was at school in the 1980s, I'm pretty sure I recall reading somewhere (possibly outdated) that a billion was 10^12, but by the time I started paying any attention to financial news in the 1990s, I'm sure word had definitely got around that we were now using the same value as the USA, 10^9 (eg, the BBC would report, "the Government is to spend three billion that's three thousand million pounds on.." (although I may be imagining this particular example, I am sure that there were indeed frequent instances where the media went to some pain to explain what exactly was meant by 'billion')).
Mind you, at the same time, the world population figures were floating around at the 3 - 4 billion mark.. Probably when I was younger I didn't think through exactly what that meant (billion, schmillion..), although it's clear that the 10^9 value must have been meant even then..
According to a mostly-non-fictional encyclopaedia, the UK Government adopted the "short scale" value of 'billion' in 1974:
http://en.wikipedia.org/wiki/Billion (word)
(the cited reference is to a recent newspaper article which merely notes this as an aside, not to a contemporary primary source)
I had assumed that this effect would have rippled around the world, in order to avoid confusion, but, according to the same Wikipedia article, it would appear that most non-English-speaking
European-language-speaking countries still use the "long scale" value (and that most non-European-language-speaking countries often tend to use their own counting systems).
Given that these are numbers in very specialist use (other than as $BIGNUM which we ordinary folk can really barely conceive of), I would imagine that anybody who does need to precisely and specifically refer to 10^9 or 10^12, etc, values would be very sure to make certain that all parties to the discussion knew exactly what was being referred to..
David M. Edinburgh, Scotland. (en,fr,(de)