Forget the talk of "fiscal space" – the economic jargon for the amount of extra money that might be available to the incoming government in the years ahead, writes RTÉ's Political Reporter Brian Dowling.

Instead, it might be better to focus on one word: forecasts.

The scale of what might be available in the next five years depends on whether the economy grows in line with the forecasts.

In its last assessment, the Fiscal Advisory Council had something to say about economic forecasts.

It pointed out that the forecast for over 4% growth for this year, as with any year, is subject to change. It could be better. It might be worse.

It could end up closer to 8%, which would be great. But it could fall closer to 1%, which wouldn't be so good.

Understandably, manifesto plans tend to be built around economic forecasts provided by the Department of Finance.

In broad terms, there is an expectation that the economy will grow by an average of 3% in each of the next five years.

Economist Colm McCarthy spoke about this on yesterday's The Week in Politics.

Economy explained using a 'fiscal cake'

Now in the past he has been called in by government to help clean up the mess when things went badly wrong. Remember the dreaded "An Bord Snip"? - the group tasked with identifying ways of slashing public spending to get the finances under control.

Basically, Mr McCarthy is worried that politicians risk putting too much store on the current economic forecasts.

Events outside of Ireland's control could rapidly undo the calculations – events such as another crisis in the euro; trouble in the sovereign bond markets or a steeper global slowdown.

And because of the continuing high levels of debt, even though they are falling and more manageable, Ireland is vulnerable.

It still has to borrow in the bond markets and we still have to rollover large amounts of debt in the years ahead.

So instead of building plans around the amount of extra money, the so-called fiscal space, whether that is €8 billion or €12 billion, he is asking: What if all the forecasts prove to be wrong?

They have been wrong in the past.

His answer is protect what we have now; try to move to budget break-even and budget surplus as soon as possible and hold firm for a few years.

It will be interesting to see if there are many takers for that option as the first full week of Election 2016 kicks off today.

By Brian Dowling, of RTÉ's Political Staff