Friday 8 July 2011

Fuel Duty Fun

From The Daily Mail:

The Treasury is facing a £637 million deficit after fuel sales dropped by one billion litres this year, the AA revealed.

Service stations in the UK sold 835 million fewer litres of petrol and 247 million fewer litres of diesel in January to March 2011 compared to the same period three years earlier. The [15.2] per cent dip in petrol sales and the 6 per cent fall in diesel sales were caused by higher fuel costs and consumers tightening their belts.


Shock horrors! Fuel prices up and sales down! The demand for fuel is price-elastic! Moreover, the demand for diesel (primarily lorries, so we'd expect diesel sales to fall in line with sales of food and so on) is far less price-elastic than the demand for petrol (which is discretionary spending to some extent). Well who'd have thought?

More to the point, the £637 million tax shortfall is mathematically correct but logically flawed. Let's stick those figures in a spreadsheet:

First quarter 2008:
Million litres of petrol sold = 5,493
Million litres of diesel sold = 4,117
Total = 9,610
Average price (from here) = 106 pence/litre
Fuel duty = 53.65 pence/litre

Change:
Petrol sales down 15.2% = 835 million litres
Diesel sales down 6% = 247 million litres
Total = 1,082

First quarter 2011:
Million litres of petrol sold = 4,658
Million litres of diesel sold = 3,870
Total = 8,528
Average price (estimate) = 135 pence/litre
Fuel duty = 58.95 pence/litre

So how much is the fall in tax revenues?

If we just multiply 1,082 million litres by 58.95 pence, we arrive at £638 million (the AA's figure).

Oh no, it isn't!

The £637 million figure is of course complete nonsense and is comparing apples with pears on several levels - for example, they overlook VAT - which used to be 17.5/117.5 of a smaller number and is now 20/120 of a bigger number.

So how much is the increase in tax revenues?

The true tax per litre in the first quarter of 2008 was 69 pence (15p VAT and 54p fuel duty); in the first quarter of 2011 it was 81 pence (22p VAT and 59p fuel duty). So the AA could argue (if it so wished) that the tax shortfall is £881 million (1,082 million litres x 81p), but it would be far more correct to say that total revenues were £273 million higher in first quarter 2011 than in first quarter 2008:

Q1 2011: 8,528 million litres x 81p = £6,946 million
Q1 2008: 9,610 million litres x 69p = £6,673 million
£6,946 million - £6,673 = £273 million.

So it's quite clear we are still not past the top of the Laffer Curve (although we may be getting near it) and there is no 'revenue shortfall'. Whether you think that fuel duty is a better or a worse tax than other taxes is a separate issue; to my mind it's like Land Value Tax for roads, so is on the "good" side of the line, as opposed to VAT generally, income tax, National Insurance etc, which are on the "bad" side of the line.

Just sayin', is all.

5 comments:

Bayard said...

Ah, but the Treasury have already counted in the increase in VAT as part of the unrealistic sum it hoped to raise by putting VAT up by 2.5%. So the shortfall is (9610 x .54)-(8528x.59)=£158M. In addition, the Treasury could have been assuming that fuel prices would not rise and hence consumption fall, therefore the £881M figure would be accurate for the amount the actual amount the Treasury are getting is smaller than what they thought they would be getting.

Mark Wadsworth said...

B, you could argue that the shortfall is £158 m, but that seems a bit off piste - in HM Treasury they don't do dynamic effects (or factor in oil price chanfes), they think that if they put up fuel duty from 54p to 59p that sales remain the same and revenues go up by 5/54.

I don't know where you get £881 m; 9,610 m x extra 5p = £481 m.

Bayard said...

"I don't know where you get £881 m; 9,610 m x extra 5p = £481 m."

From your post: "So the AA could argue (if it so wished) that the tax shortfall is £881 million (1,082 million litres x 81p)"

"in HM Treasury they don't do dynamic effects"

Yeah, I didn't think they employed many in the way of economists.

JohnM said...

But we are ignoring the industry-specific fuel costs.
Those registered for VAT claim it back.
Fuel cost, and hence tax, are set against profit for tax purpose.
So higher fuel cost means less profit and less tax.

Mark Wadsworth said...

JM, true, businesses can usually offset the costs against tax (except privately used company cars, where the tax and NIC on the benefit far exceed the value of the corporation tax relief).

Reclaimable VAT is a red herring. Just pretend that business-to-business supplies were exempt of VAT.