There was a brief gas shortage in the US not too long ago. People started to panic that they wouldn't have enough gas, so they ran out to the gas stations and filled up while the local stations had enough supply. Some people went to the extreme to fill up plastic bins and bags to ensure they had enough supply for themselves, leaving even less for others. More people started to go to the stations to get gas before they ran out. This is an example of a _______________ feedback loop