These new things create opportunities for ribbon-cutting ceremonies that give politicians favorable free publicity in the media. But nobody holds ribbon-cutting ceremonies for filling in potholes or repairing bridges.

The whole process is biased toward doing new things, even if the repair and maintenance of existing infrastructure would serve the public interest better.

But, even in the unlikely event that the public interest triumphs over special interests, there is another very important difference between repair and maintenance activities, on the one hand, versus building new things on the other.

New things require long delays before they can get started, especially when they have to be done by politicians. Someone once said that Congress would take 30 days to make instant coffee-- and Congress is just the beginning of the delays, as all sorts of competing interests jockey for position at the public trough.

Just putting together an environmental impact report for something new to be built can be a long process, especially if its findings are challenged by environmental extremists, who pay very little price for challenging, even if the delays caused by their challenges cost others millions of dollars.

In short, it can be years before the money that is supposed to stimulate the economy actually gets into the economy. And nobody knows what the economy will be like when that money finally gets into circulation.

A common problem with government economic policies in general is that it is very hard to predict how long it will be before the policy actually affects the economy. An economic stimulus policy created during a contraction in demand can take effect during an inflationary expansion of demand-- and fuel still more inflation.

A trillion dollars or so, created out of thin air by a government that already has a huge deficit, can set off another round of inflation that can take some very painful new policies to bring under control-- or can have even more painful effects, if it is not brought under control. The new administration may need that get-out-of-jail-free card.