what should i understand from the merits of his statements??? lol bitter for wad?? 
 
i am sorry, i listen to his speech and see his fb posting, i really dont see any merits for SIA or even needing to do a study for such feasibility. Why? because the whole global airline industry is hit, and no gov now in a sane mind will undermine their national carriers competitiveness thru the means of a tax. Esp those with a bigger carbon footprint and bigger domestic market than sg. What elasticities he talking about? unless SIA is the only premium service airline in sg airspace forever.
 I am sure economics professor knows what is basic law of demand and supply, and of course dead weight causes by tax.
And if he just wan to ask if its possible, tts even stupidier and at the worst possible timing. Does he really speak on the perspective of SIA surviving or the environment surviving? The scary part is not him talking about environment tax, is the timing and the need for him to defend this. Is there really nothing else to ask about?
		
 
Economic professor will also tell chiu deadweight loss ish only one side of the story.
The other side ish any goot tax will make the value resulting from the tax (monetary or otherwise) greater than the deadweight loss, therefore resulting in a net gain to ebryone.
On the surface companies donch rike tax because their deadweight loss ish taken from them.
But here ish special situation where large chunk of the tax ish channeled back to somehow SIA to keep them afloat. Which may be possible to cover most if not all or even exceeding their deadweight loss. 
And benefits may be also spill over to society at large.
E.g. If SIA keep the revenue and ownself pay the benched cabin crew, it ish useless.
But if govt take the revenue as tax to gib horsepeter, then horsepeter can pay to train and hire cabin crew to be caregivers. 
Thish ish value to cabin crew and by extension SIA since their personnel receive additional medical training.
Cabin crew ish paid income subsidized by govt (although ish actually indirectly by SIA).
Horsepeter and by extention society benefit from their services.
Not to mention environmental benefits, which may be for the moment ignored due to economic concerns.
And if true then jamus taking the tiem nao to call thish, ish not throwing rock down the well at SIA, but ish in fact helping SIA and broader society.