Use of phrase " times less than"

[Raymott]

I get upset when I hear or read the media regularly using poorly constructed sentences ( especially when the meaning may be ambiguous ) which then seem to become the norm very quickly with young native English speakers.

Don't we all! (OK, most of us).

[5jj]

I have noticed the increasing use of what I consider to be incorrect comparison within the english media and would value another opinion regarding this. An example taken from the BBC today follows:
"the UCI said the concentration found by the laboratory was estimated at 50 picograms - 400 times less than anti-doping laboratories"

Could someone please tell me what this statement means and also what the writer may think that it means.

This seems to be used very often and I am not sure if it is deemed to be correct and I am out of date or if it is just poor use of the language.

Yes, you are out of date - but so am I.

I assume that the speaker means that the anti-doping laboratories' concentration was estimated at 400 x 50 = 20,000, but one cannot be certain. S/he might meaning that the reduction was 20,000, so the anti-doping laboratories' concentration was 20,040. Such expressions lack clarity.

I have seen similar confusion with: We had 50 enquiries today, 100% less than yesterday. I assume that the speaker meant that there were 100 enquiries yesterday, though that would seem to me to be 50% less (or fewer!).

In my own speaking and writing I try to avoid using such expressions unless I can be absolutely clear, as in: The January sales of £120m were 20% up on the December figures of £100m, the biggest percentage increase for eleven months.

Note that in my example I put in the actual figures for January and the word percentage. It may well be that last July's figure's were £500m and August's were £550m. This is a a bigger increas (£50m as against £20m), but a smaller percentage (10% as against 20%).

My only suggestion is to take verbal descriptions of figures using percentages or such expressions as times, more than, less than, etc with a large pinch of salt. If you can, ask the writer/reader to give you the actual figure.