Is there a purpose for a debt celing?

On Bloomberg TV, “Political Capital” host Al Hunt asked Geithner if he believes “we ought to just eliminate the debt ceiling.” “Oh, absolutely,” Geithner said. ... “It would have been time a long time ago to eliminate it. The sooner the better."

Households do not have debt ceilings. Companies do not have debt ceilings. Why should a government have a debt ceiling? The answer is simple. The Congress and the citizens cannot be trusted to hold down spending so this imposes a target on the size of the deficit. Imposing rules on potential bad behavior is time honored. 

The debt ceilings have always been raised, but the discussion about the size of the debt serves a useful purpose. Rating agencies are not upset with the debt ceiling. They are upset with the size of the debt. Hence, it is hard to argue that eliminating the debt ceiling will be good for the country. I would argue there is no need to ban the ceiling. However, a debt ceiling tied to the size of the economy or more regular reviews would make sense.