SEVEN jokes were enough to carry Chancellor Philip Hammond through a jovial Budget presentation, but they could not in the end hide the grim reality he was revealing to us. It often takes a couple of days for the true nature of a Budget to sink in.

In this case, it could be sought in the small print of forecasts for UK economic growth during the next five years, all down by nearly 0.5 per cent from previous estimates. It may not sound much till you translate it into cash terms. It represents an annual loss of up to £25 billion worth of production – that much less for a consuming country to enjoy, that much less for a trading nation to export. It sounds all the grimmer when we set the projections side by side with what the UK economy was able to achieve in the quite recent past.

During the three decades after the Second World War, we could rely on growth of up to three per cent a year, enough for more or less full employment. The figure reached one peak of four per cent in 1979, just before Mrs Thatcher came in, and her policies quickly plunged the country deep into recession.

But in the longer term they did us good, so that in 1988 the growth rate reached another peak of five per cent, just in time for New Labour to throw it away. A decade later, under Gordon Brown, came the biggest recession since the 1930s. After 2009, in which year the UK economy actually shrank, its performance has remained feeble – right until the present day, in fact.

However, there is a difference to the cycle this time. In the old days, after such a deep trough we would normally have expected a strong bounce back and the resumption of the trend growth rate. As of now, there is no sign of any such thing. Recovery may be under way, sort of, yet the UK economy looks scarcely capable of attaining even two per cent growth. Nothing on the horizon hints at any improvement.

Foreigners used to talk about the British disease, because even at its best our economic performance lagged behind that of our European neighbours. Now it seems we might have caught the Japanese disease too. Time was when Japan could leave the western economies standing, but it has failed to rise from the doldrums of its so-called Lost Decade in the 1980s. Then, for problems caused by the preceding boom, a deflation was judged necessary, yet budget deficits persisted because no recovery ever followed.

An ageing population made it impossible to keep welfare costs down, as the old folk, with decades of savings behind them, kept up unsustainable levels of consumption, and so of imports. For 30 years, Japan has been unable to get out of this bind.

Has it been showing the UK the fate that awaits an advanced country unable to solve its problems? That is the haunting fear for us now. We, too, may have passed a point from which there is no return for a mature, perhaps senile, economy.

Although I’ve developed this theme to show the condition we are in, or might be in, it is not what I want most to discuss today. I’m much more concerned about the effects on Scotland, and how we can remedy them through independence or at least mitigate them through what could be called quasi-independent measures, those available to us short of full fiscal freedom.

As Unionists keep reminding us, we are highly integrated with the UK economy. Is there an escape, or are we so locked in this fatal embrace that the cure would be worse than the disease?

The first thing to say is that being highly integrated into the UK economy does not make us uniform with the rest of it. Scotland has been lucky to see little of the asset bubbles by which the Government in London has sought to pump up sluggish demand in England. But we do need a bigger labour force if we are to achieve higher growth, and this can only come through immigration, so English hostility to foreigners is harmful to us.

It may seem a flimsy basis for a new economic order for Scotland, but something similar has happened on these islands before. After the 26 counties of the Irish Free State won their independence in 1922 they long remained completely subordinate to the economy of Great Britain, and exported hardly anything elsewhere. Their role was to supply its industrial cities with food, mainly beef and dairy products. They had no industry of their own, except for a bit of this and that in Dublin, such as Guinness.

It was not a state of affairs disagreeable to the victors in the civil war, who wanted the country to return to bucolic Celtic purity, with “dancing at the crossroads,’ as Eamonn de Valera put it. He and his comrades-in-arms also expected the end of British imperialism to bring a reversal of the heavy emigration that had lasted since the great famine of the 1840s, and they were shocked to see it just carry on – not till the 1960s did the population start to go up again. Irish nationalists, like the Scottish political class of today, did not think in economic terms.

Since the Irish believed British free trade had caused all the problems, they saw protectionism as the solution. Ireland set out to become as self-sufficient as possible – for example, in energy, though it had none of the resources other countries could rely on.

The tidal power of the River Shannon was harnessed, while (my favourite) Bord na Móna sought to industrialise the digging of peat. Bord na Móna is still going strong, although it has given up on peat to become the main public agency for the whole range of renewables. In any case, after a half-a-century of all this footling about it was clear that, whatever the formula for future prosperity might be, Ireland had not discovered it.

Even in 1973, when Ireland joined the EU, 90 per cent of its exports still went to the UK. Free access to wider markets made a difference, as did, at length, a common European currency. But the benefits did not follow automatically.

At first, governments of both Fianna Fail and Fine Gael pursued a course rather like the pork-barrel politics the SNP proposes for Scotland, except there was far more spend than tax. Not until 1987 did the two big Irish parties agree on the so-called Tallaght Strategy of economic reform: cuts, encouragement of competition, no borrowing to finance current expenditure, low corporate taxes to lure foreign investors, remodelled welfare (which by UK standards had not been generous anyway).

The Celtic Tiger sprang into motion. By 2000 Ireland had become one of the world’s wealthiest nations. The economy grew by five or six per cent a year. Full employment was reached and Irish exiles started coming home again. Workers’ wages soon surpassed those in most other EU member states, yet income tax was halved.

None of this averted the consequences of the global economic crash of 2008, in which Ireland was among the hardest hit of all. But one thing the Irish now know, as they pick themselves up and dust themselves off again, is that they will never return to the failed policies of the early Republic. For them, it is still going to be full steam ahead with free markets.

And by the way, in the course of all this, the UK share of Irish exports has come down to 13 per cent, while the share of imports has fallen to 31 per cent. Today, Ireland exports to Belgium as much as it exports to Britain.

So it is simply not true, as our home-grown Unionists claim, that the independence of Scotland will be hopelessly compromised by the existing level of trade with England (about 65 per cent of the total). To change the pattern of trade, we need only to adopt the right policies. Up to now, alas, the Scottish Government has failed to do that, and seems slated to repeat its mistake in its own Budget next month.