By BBC News political editor Andrew Marr
Who says election campaigns are meaningless?
The first week of this 2001 campaign has been unexpected, serious and meaty.
Far from being a predictable exchange of jeering, it has revealed serious differences between the parties, and problems for all of them.
" Far from being a predictable exchange of jeering, it has revealed serious differences between the parties, and problems for all of them "
The first big argument has been over the economy - above all, tax and how to pay for better public services in the next five years.
A leak of Labour's election manifesto confirmed that they will repeat their 1997 promise not to raise the basic or higher rate of income tax.
This will reassure many voters, but leaves them with a longer-term problem.
Tax and spend dilemma
Tony Blair calls this 'the investment government'. Gordon Brown, the chancellor, is spending 3.7% more a year to improve schools, hospitals and other public services - more than the growth of the economy as a whole.
He's been able to pay for it with earlier tax rises, one-off sales of telecoms licences and savings from lower unemployment and repaid debt.
" But it's simple logic that this can't go on indefinitely without either higher taxes or higher borrowing to fund the gap "
But it's simple logic that this can't go on indefinitely without either higher taxes or higher borrowing to fund the gap.
So what would Labour do half-way into the next Parliament if it won again?
The answer emerging from a series of early-morning press conferences is that if push comes to shove, the spending rises would come down again.
" If, however, it turned out that the change is only for a few years before we return to the older trend, how historic would that seem? "
Naturally, Labour hopes that further 'good management of the economy' - pressing down on unemployment, fraud, debt - would still allow higher-than-growth increases for education, health and transport.
It matters a lot, because so much of Labour's pitch to the country is that it will reverse a long period of 'Tory under-investment'.
Yes, there had to be a couple of austere years of 'tough choices' early on; but today's higher spending signals, to use a favoured New Labour phrase, 'an historic step-change'.
If, however, it turned out that the change is only for a few years before we return to the older trend, how historic would that seem?
Tory tax plans
The Tories, though, still have serious explaining of their own to do.
They have been fighting to demonstrate that their proposed £8bn of tax cuts can be paid for through cracking down on welfare budgets, bureaucracy, the University loan system and fraud.
Labour - and some economists - argue that there is a lot of wishful thinking in the plan; and worse, that Conservative plans for changes to the national insurance system and other vaguer tax promises add up to a £16.7bn 'black hole'.
" The Tories hotly contest all that, and no-one should take anyone's apparently detailed figures too seriously "
Further, a Labour analysis of the Conservative manifesto 'Time for Common Sense' argues that it reveals £6bn of uncosted spending increases, ranging from a big increase in the Territorial and regular Army, to asylum centres, more prison places and new health spending.
The Tories hotly contest all that, and no-one should take anyone's apparently detailed figures too seriously.
But the Labour operation is very similar to the Tories' famous 'Labour's Tax Bombshell' attack on their manifesto during the 1992 general election and may yet prove as damaging.
Criss-crossing the country
Labour also points out that the Tory manifesto contains no inflation targets or fiscal rules of their own.
The Liberal Democrat leader, Charles Kennedy, has spent most of the first few days criss-crossing the country by plane to reach voters in key marginal areas via local radio, press and television, while attacking both the bigger parties - the Tories for their arithmetic and cuts agenda, and Labour for its lack of ambition.
" He is the only British party leader with a clear agenda for tax rises to pay for better services "
He is the only British party leader with a clear agenda for tax rises to pay for better services.
This argument has been the fuel of the first week but the cavalcade, the style of the parties, has been interesting too.
Apart from Mr Kennedy's jet-setting, Tony Blair's stage-managed announcement of the election date at a south London girls comprehensive school drew jeers and winces from many media commentators.
They have been unimpressed too by the sanitised whistle-stop conversations in his bus tours.
Mr Hague, meanwhile, has run a campaign which in the first few days has been far smoother and more professional than most of us expected.
His manifesto launch was early, gaffe-free and eloquent.
" But both Mr Blair and Mr Kennedy have made themselves far more available to media cross-questioning at press conferences than the Tory leader "
But both Mr Blair and Mr Kennedy have made themselves far more available to media cross-questioning at press conferences than the Tory leader.
If he spends next week as far away from real debate, he will find the critical spotlight turning on him.
Meanwhile... the sun is shining and this marathon has many foot-blistering miles still to go.