Mosquito Math -- Bad science?

I was reading a report on the efficacy of an anti-mosquito chemical, and I came across this:

Quote:

In a study of citronella candles using human test subjects, Lindsay et al. (1996) reported that the overall percent reduction in mosquito bites provided by the citronella candles was 42.3% and by plain candles was 23.1%. Considering the reduction in mosquito biting activity produced by the act of burning candles, the addition of 3% citronella to candles further decreased biting activity by only 19.2%.

Uh, no, it looks to me like the addition of Citronella further decreased the biting activity by a *whopping* 83.1%.
. . . . . . . . (42.3-23.1)÷23.1

The author seems to have confused the difference between a percentage reduction and a percentage *point* reduction.

Am I missing something?

The report is written in scientific jargon but it's poorly identified. There's only an author name, not any institution, nor any hint of where it might have been published, if anywhere.

Quote: MichaelBluejay

The author seems to have confused the difference between a percentage reduction and a percentage *point* reduction.

Am I missing something?

It seems to me you're right. People are often clueless regarding percentages.

Lat year the VAT went from an already outrageous 15% to 16%. Many politicians defended it as a "mere 1% increase." When, as you noted above, that's one percentage point. The increase is 6.66666666666%

Quote: Nareed

It seems to me you're right. People are often clueless regarding percentages.

Thats why people don't understand slot percentages. When
they raise it from 5.2% to 7.2%, they think 'big deal, its only
2%.' When its actually a 38.5% increase.

duplicate ...

Quote: MichaelBluejay

The report is written in scientific jargon but it's poorly identified. There's only an author name, not any institution, nor any hint of where it might have been published, if anywhere.

That's usually a very good indication of the fact that reading it is going to be a waste of time :)

A number of years ago, I got called into the boss's office and was told that as part of an overall cost-cutting move, my commission rate was going to be lowered, but DON'T GET UPSET! It's only going to go down 2%!

Oh, that's not so bad, I thought. And then I was told it was going to go from 12% to 10%, and I freaked. The guy couldn't understand, that was a cut of 16.67%.

I got a different job, and negotiated 18% commission rate on fewer sales, keeping me even with where I'd been to begin with.