How are yellow peppers different from green and red peppers?

The green pepper is harvested before completely ripening. The reason for the price difference between colored and green peppers is the amount of spoilage that occurs as you allow peppers to ripen. Ripened peppers have a very short shelf life compared to green.

I think there is a problem inherent in the question. I have noticed that in America, the question makes sense, but in Europe, typically all colors of bell peppers are lumped together at the same price. I have always assumed this was due to the above statement, where in the US the price difference is due to the general nature of distribution and supply demand incorporating shelf life, where as, in Europe there is not as much market force, since most food is grown/sold somewhat locally, and the pressure is not that, since all the produce is typically 'fresh'. More feedback welcomed.