If you've ever eaten a potato in any form over the least decade—whether it's French fried, baked, mashed, or roasted, then you've likely paid way too much, albeit unknowingly. Yes, those coveted fast food fries you've been eating multiple times a week should have cost you much less than you have been paying.

According to a study done by California State University—Northridge business law professor Melanie Williams, potato farmers across the United States from 2004-2012 formed a collective, limiting their yearly potato crop output, which indirectly raised the price of potato related food consumed by the general public.

Simply put, because America's potato farmers decided to limit the land they would use to grow potatoes, the market price for their product would rise in accordance to the laws of supply & demand. That means those McDonald's fries are more expensive because the people that sell their potatoes to McDonald's is charging them more–the trickle down effect in perfect play here.

Just how much more expensive were we paying for potatoes? Williams' research indicates that the wholesale price for our beloved spuds inflated between 24% to a ridiculous 49% between 2004-2012.

Because of certain exemptions granted by a federal law in the 1920s, agricultural associations such as the so-called "Potato Cartel" were allowed to control how much farmland they decide to use. Their decision to produce less hurts consumers by driving prices up. What's more, the lack of regulation creates a legal grey area surrounding the practice and could haunt consumers again in the future.