A recent global report finally ranks Hong Kong first in something.

What we unfortunately rank first in is the cost of petrol.

This, as might be expected, generated outrage. A Hong Kong Automobile Association spokesman, James Kong Yat-hung, was quoted as saying that the price of petrol was "ridiculous". He, as might be expected, called upon the SAR government to take action.

A closer reading of the report indicates that the claim, as the Automobile Association would have it, that Hong Kong is "very expensive compared to other countries" requires some selective reading of the data. It is true that the local cost of just under $2 per liter, about HK$15.60, is more than double the cost of petrol in the United States, and more than 10 times the cost in Saudi Arabia.

But petrol costs only 1 percent more here than in Norway, which has masses of its own oil, 3 percent more than in the Netherlands and just about 7 percent more than in Britain - amounts that are probably within the range of currency fluctuations. London, it must be remembered, also has road usage levies. So Hong Kong drivers are not really that badly off.

A good portion of the local cost is tax, so the government could move us down these global rankings if it wished. But why are lower petrol prices a good thing? At best, it would mean less tax revenue. At worst, people would drive more. Why would anyone - and by anyone, I mean society - want that? More driving would result in more pollution and more congestion, greater demand for space to be allocated unproductively to parking and greater requirements for expenditure on roads. It is not as if personal motoring is a necessity here: Public transportation is good and goes just about everywhere - and there is generally no need for people to live in places where it does not go.

In any case, the cost of driving depends little on the cost of petrol. The fixed costs of car ownership are high. Cars are expensive and they incur huge registration fees. Then there are insurance and parking spaces, whose net value can exceed the cost of the car. But petrol does not even figure highly in the marginal cost of driving. Parking alone will set one back HK$30 or more per hour, i.e., about 2 liters of petrol. Petrol is not the major expense in either car ownership or driving.

Which means, motorists might argue, one might as well lower the cost because driving is, as far as petrol is concerned, price-inelastic: People will not drive more just because the cost of petrol goes down a couple of notches. But all this will do is transfer money from the government to motorists. Indeed, the opposite seems more attractive: Given that driving is not sensitive to the cost of petrol - people who wish to drive will drive anyway - the government might as well raise the tax and thus generate more revenue. It is not as if car owners cannot afford it. And if it raises the tax high enough, some motorists might actually think twice about the entire exercise.

Public transport can be exempted from the petrol tax, or at least any increase, keeping the cost down, and any additional petrol tax revenue can go to subsidizing fares.

Aspersions were cast on petrol retailers by both the Automobile Association and the Consumer Council, noting that petrol prices did not decline in line with crude oil costs. There may be several reasons for this, but if there is "overcharging", whatever that means, it can be corrected with regulation. But there is no benefit to society to return any excess to motorists; let these sums, again, go to subsidizing the fares of the majority of people who use public transport.

Subsidies need not be across the board: They can be restricted to students or the elderly, or go to necessary but unprofitable routes or to off-peak travel to encourage evening of the load.

Or instead, the money can go to fixing Hong Kong's taxi mess, emotions about which are rising - drivers smashed up a cab in protest last week. Hong Kong will at some point need to liberalize its taxi licensing system, either by issuing more licenses or due to competition from app-based private car booking systems. Either way, the value of a license will fall, and license holders will strenuously object. If petrol tax revenues go to easing the transition to a more economically sensible system, both drivers and passengers will be better off.

Hong Kong is supposed to be a smart place which uses economic principles in the interests of economic efficiency. So in the meantime, let us celebrate Hong Kong's place at the top of these rankings and hope it stays there. Some government policies actually work.

(HK Edition 07/29/2015 page9)