AS an expert on oil production, I am surprised that Jim Lynch (Letters, July 18) hasn’t read the recent report by Wood McKenzie that shale extraction is likely to attract much more investment than deepwater in future as it is a lower cost option. There may well still be oil and gas in the North Sea but it will require large amounts of investment at a time when capital spending is being cut and it will be costly to extract, given the difficult operating conditions.

To hear the way the Nationalists talk of oil, you would imagine that they had extracted the stuff themselves, by the sweat of their brow, only to have it cruelly plucked from their hands by the evil English. In fact, oil revenue is what we economists refer to as rental income. The income flows purely from ownership or endowment and not from the provision of any service. In other words, oil income is pure serendipity. Oil could just as easily have been found off the English coast. Do you think they would have grudged us a share in their good fortune, the way we do them?

My commiserations to the people of Aberdeen as the decline in the industry will hit them hard. However, for the rest of Scotland, oil has been nothing but a curse, being the source of a great deal of bitterness and lasting division.

John-Paul Marney,

15 Marlborough Court, Langside, Glasgow.