For a few years airlines bleated that the 7kg carry-on limit was all about safety for weight limits of the overheads to if a bag drops on someone’s head.
It appears safety has been assigned a value. Oh wait, could it always have been about revenue and the years of it being about safety were a furphy?
I recently read an article which suggested wearing as many items of clothing as possible on a flight and filling the pockets so as to reduce the baggage weight.
There is more than one way to skin a cat.
Oh dear…
I don’t think the article I read suggested trying to go quite that far…
That one definitely seemed like an extreme case! I imagine carrying a laptop or throwing on an extra jumper if it’s not too hot could get you across the line if you’re close to the limit.
One never knows about posts like this, but it is the last one attached to the article
Juhan Vaheriga
FAKE NEWS! I was travelling from Reykvjavik to London on the same flight and I was sitting on the same row. Already by boarding he was extremely arrogant. One taked place (17A) he started to behaviour extremely rude and started to sneeze very laugh and rude during at least 20-30 minutes. I really don’t know how the passengers was sitting in front of him (16A) remain at he’s place. Anyway a quite couple was sitting at 17B/C must moove. The lady was sitting just close to him moove to me as the seats 17D/E was free. Once landing I had this moron just behind me and I really feel how he wanted pushed me during all the way out of the plane. I must say that this man has evident psychological problems, he is mentally disturbed and I would not be surprised if he take some drugs.
It may pay to read the fine print, or in this instance just the requirements per the airlines web site.
A thin laptop counts as “one small item” which must be included in your weight limit! 
Being lighter than many I might think an extra kilo or two is ok for some. Interestingly you can purchase an extra 3kg of carry on for a little less than the cost of adding 20kg of checked luggage to a starter fare! 
Why it is less effort for Jetstar to handle your 20kg of checked luggage than for you to handle the 3kg personally may have already been explained? 
P.S.
Even in Jetstar’s slightly more premium ‘business class’ where it previously was 20kg carry on it’s now 14kg with no single item over 7kg. I guess that still 6.9kg in a large sized cloth shopping bag for the light traveller? More discerning passengers may make other choices. 
I think in the bigger scheme of things safety has always been assigned a value - one that the airlines don’t want to admit and the customer doesn’t want to know.
From the article:
Where you’ll really pay is if you don’t book your checked baggage in advance. Checking a 15kg bag on Jetstar will cost $60 at the gate. On Tigerair, the fee is $75. Jump up to 20kg and Tigerair will slug you $85, while Jetstar will want an eye-watering $115. There’s a fair chance your ticket cost less than that.
The ticket was only that cheap if you live in the big smoke and you are flying to another big smoke, otherwise its but a fraction of the wallet pilfering the airlines will do …
Appending this airplane safety report here since the difference between this and a bit of carryon or over allowance seems ‘big’. Note Boeing and Airbus ‘enjoy’ buggy software, but look over there at that oversized luggage (yes, weight and balance is important, but not much more than having lit cockpit displays, especially in IFR conditions).
No Aussie airports with a precision approach, runway heading 270? Lucky us.
