Most of us reporting the federal budget get little sleep on the night itself. We are busy "unwinding".

But for two officers of the federal Treasury it's different. They get little sleep the night before. They literally attempt to sleep with the budget papers, in a cage in the basement of Parliament House. One of them has been doing it for years.

Printed under tight security, the documents are taken to the basement late on Monday and then guarded closely throughout the night until Tuesday morning when they are whisked up in the lift and stacked inside the committee rooms in which they will be handed out.

That's how important it is to the Treasury to keep them secret. But it's hard to work out why.

One year, Labor treasurer John Kerin abandoned the lock-up and simply handed them out before he delivered his speech. The world still turned. Earlier, journalist Laurie Oakes got hold of the entire budget speech and read it to Channel Ten cameras. Again, the world turned.

We're told the reason for the secrecy is because the budget contains "market-sensitive" information. If anyone knew what was in it before anyone else they could make a killing on financial markets, or buying up beer before it was more heavily taxed.

But these days most of the budget measures are known in advance. The few surprises that remain are held back for theatre, not to protect the market.

The budget has become more of a US-style State of the Union address than a statement of accounts. Although it is delivered by the Treasurer rather than the Prime Minister, its primary purpose is to outline the government's program for the year ahead, which makes this year's pre-election budget not that unusual.

It is true that this year the parliament won't have much time to consider the budget before it is dissolved, but the budget bills are in need of less consideration than is widely believed.

The constitution says they only cover spending, not revenue. The existing arrangements for collecting revenue continue whether or not there's a budget and whether or not it is passed. If the Senate had knocked back prime minister Gough Whitlam's budget in 1975, as it was about to, the government would have still collected revenue, it just wouldn't have been able to spend it.

Actually it would have still been able to spend a good deal of it. Budget bills are only required for spending for the "ordinary annual services of the government". Other spending, in fact most of it, is on payments to the states and grants. Medicare refunds, pensions, grants to the states and the like are authorised by separate so-called standing appropriations which continue whether or not the budget bills are passed.

Decisions about whether to pass the core budget bills are little more than decisions about whether or not to re-authorise the payment of public servants, which is why they are almost always made swiftly.

The most important things about the budget, apart from the razzmatazz and the setting out of priorities, are the forecasts. And they've only become important since the late 1980s.

Before then the budget papers (rather inexpertly) forecast spending and revenue for just one year ahead. The Hawke government's first finance minister John Dawkins drove a change to four years. Now no one would think of looking at a budget measure without knowing what it would do to the "forward estimates" - the four financial years from budget night.

So accepted have the forward estimates become that these days the impact of budget measures is usually quoted over four years rather than one, often without acknowledgment. So if you're told on budget night that a measure will cost $4 billion, it might mean $4 billion per year, or it might mean $1 billion per year. It's wise to check. Treasurers aren't above choosing the time frame to quote in order to make what they are proposing seem either big or small.

It's a less than perfect process. Journalists are locked up with the papers for less time than the Treasury officers who sleep with them downstairs. But it is the only important annual platform we've got for examining the government's plans. Other nations have far less. The British budget deals only with revenue. The US budget process is a mess.

We should be grateful for the opportunity we are about to be given on May 3. We should make the most of it.

Peter Martin is economics editor of The Age.

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