Ronny - that is a good question. And there are a lot of answers.

Intervention in the economy involves change from free market conditions. Since the free market is generally the most efficient, intervention will generally lead to some inefficiency. That is, while it may benefit some, the cost to others will be greater than the benefit. Criticisms come loudly from those who bear the cost of the intervention, or from those who measure and are aware of the costs.

Another criticism comes from the lag time from implementing intervention and obtaining a desired result. There is also lag time in measuring current conditions. This makes it difficult to know when an economy is lagging in time to make a policy decision and implement a stimulus before a recovery has occurred on its own, which could result in inflationary pressures that were not intended. The lags have resulted in government acting too late or effectively doing the wrong thing at the time it was done - when measured way after the fact when results are known.

Another criticism of government intervention is political motivation for building personal advantage. 

I expect other folks may have more ideas on this. It is a good topic for discussion.

Good points, Jack. Here in the US, the media has been "warning" for months that we're in a recession despite the lack of data that strictly defines a recession -- a decline in gross domestic product (GDP) for two consecutive quarters.

Of course, once that's been measured, the economic conditions that cause the recession have been at work for six months...

The President and Congress have thus moved in their own glacially swift manner to unveil an economic stimulus package designed to boost the economy out of its doldrums. Primarily, it centers around tax breaks to business and tax rebates to individuals.

(A side question: if tax breaks for business and tax rebates for individuals are good for the economy, then why don't we do it all the time...?)

I'm not sure exactly when the tax breaks for business will kick in, but it will take a few months to manifest itself in business operations. Meanwhile, the tax rebate checks won't start shipping for a few months.

Bottom line, then, is the economic factors contributing to recessionary conditions will have been at work for close to a year before we recognized the problem and acted to attempt to correct it. It will be will over a year by the time we figure out whether we've acted rightly or not, too.

That's a long lag time for steering a ship, especially when you're navigating through icebergs...