If your going to talk about reading comprehension, realize I didn’t post about going to church. I’m agnostic, I’d never say that. For your reading (or lack thereof) pleasure, here is the quote.
Secondly, it most certainly is supply and demand in the case of the printers. You will tend to get better rates and better prices that sell more product. The more product they sell (therefore higher demand), then can afford to drop the price. If, for instance, there was a sudden shortage of ink cartridges, you would see the price of Ink Printers rise substantially because the supply of cartidges has been decreased, and until demand shifts and brings the price back under control, the price WILL RISE. But the reason they drop the price is because they are in a perfect competition type of market. Perfect competition means that there are a number of products that are relatively simliar and can be substituted for each other without any major changes or drop offs in quality. Because of the ability to have substituions, the prices can and will change significantly.
Gasoline has no direct substitue, therefore it will not behave the same as something that has a number of direct substitues availble for it.
OPEC is a cartel, something that is outlawed in the United States (for more information on cartels and other groups like them, check out wikipedia or other search engines for information on Standard Oil in the early part of last century.) Cartels can choose to set their own production schedules or levels, depending on what they see fit. They have decided to set one single production level as their own, therefore operating as a monopolistic entity. Therefore, any minimal change they may see either in the supply or demand side of their business, and they will alter the amount of oil they are pumping, therefore changing the supply of oil, and causing immediate impacts in the price of oil. Ever wonder why we had gas again at 89 cents a gallon directly after 9/11? It was because the demand for oil went SHARPLY down, and OPEC could not correct their supply side down fast enough to keep the prices in line.
Whether you want to admit it or not, the prices are a function of supply and demand on a worldwide scale. Don’t even get me started on China, Iran, Iraq, Nigeria, and other areas of the world that impact the price either thru increased consumption or political strife.