Leading article: The Chancellor assumes the mantle of his predecessor

After the raucous reception for the Chancellor from the Opposition benches, the eye-catching concession on inheritance tax, and the promises of higher spending on health and schools, it is tempting to wonder what yesterday's parliamentary occasion might have looked and sounded like without the events of the past two weeks. Less a pre-election budget without the election – as the Shadow Chancellor, George Osborne, called it scornfully – what we had in this combined Pre-Budget Report and Comprehensive Spending Review was one giant defensive swerve.

To call Alastair Darling's report more political than economic would be an understatement. One clear purpose, if not the central purpose, was to neutralise last week's Conservative initiatives, delivered when an election did indeed appear imminent. From Mr Darling's acknowledgement of the need to "respond to the aspiration" of the British people – his first allusion to the hated Inheritance Tax – to his pledge to use for public services the money saved from not exempting sub-millionaires, he had Mr Osborne in his sights.

As so often, though, the substance of his proposed changes was less dramatic than the presentation; in this the new Chancellor showed himself a true disciple of his predecessor. It might seem as though the Inheritance Tax allowance has been doubled overnight. In fact, the rise is no more than is already available to those who set up trusts. It is the lawyers and financial advisers who now stand to lose, not the Exchequer.

And for those in the Labour Party who regard Inheritance Tax as a legitimate tool of social solidarity – as indeed does this newspaper – Mr Darling actually conceded very little. In theory, the greater concession was his commitment to consider house prices when setting thresholds in future. Given that prices may now be falling, or at least rising far less steeply, this could be worth a great deal less than it seems.

On the taxation of non-domiciled residents, Mr Darling again challenged the Conservatives' figures. In setting time limits for tax-exempt status, while proposing a discussion of what else might be done, he conceded the possibility of change, while guaranteeing to do not a great deal. The single higher rate of capital gains tax, targeting those working in private equity, will extract more from unpopular "fat cats", but risks stinging genuine small entrepreneurs at the same time.

The environmental levy on flights, rather than air passengers, was another theft of a Conservative idea that illustrated the risks for any Opposition in giving cards away too long before an election. But this does not make it any less of a good idea. The specific environmental pledges, like his promise to meet existing commitments for international aid, were consoling in so far as there was no backsliding.

The Chancellor gave a confident, and ostensibly competent, performance. At the end, however, he left a mystery. Given the inclement global economic climate (to which he referred several times as an exclusively foreign phenomenon), the lower projected growth rate (which he admitted), and the sharp falls in both the savings rate and individual disposable income (which he left Mr Osborne to find in the small print), how does he propose to pay for higher spending on health and education? Given the experience of the NHS, it must also be asked whether higher spending is always a boon, unless accompanied by sound management and reform.

If, as it appears, Mr Darling expects the bill to be paid largely by savings across other departments, he is suffering from the same delusions as many of his august predecessors. Politically, the Chancellor bought the Government some time yesterday. Economically, we find it hard to believe that his sums add up.