Single Status Update
Explaining externalities when you do not take the class you're in seriously:
Imagine a man smoking a cigar walking down a bridge. As he is walking down that bridge, a barge is going under it. The man decides to toss his cigar over the edge of the bridge, still lit. Meanwhile, the captain of this barge has his window open because he is smoking a cigarette. The wind happens to catch the falling cigar in such a way that it hits the captain in the eye, causing him to spill his coffee all over his control panel, shorting out all control mechanisms. As the captain tries to gather himself, he slips on the coffee, hitting his head on the corner of a control panel and dies. The barge is now a floating battering ram. But from the outside, everything appears to be going as planned. But upstream is a fork in the river. Go left, and you will arrive at the next lock system where you can undergo your standard barge inspection as planned, go right and you will be headed right toward the terrorists. There happened to be a wind blowing in from the West on this day, so when it came time to decide which way to go, nature decided that this barge on this day was taking the right fork, taking the barge toward certain death. However, when the terrorists saw the approaching barge and took their offensive positions, they had no idea that the captain was already dead. This would prove to be their downfall, as the barge (which would normally have stopped at the demand of the gun toting terrorists) kept barreling forward with no man at the helm, destroying the terrorist base and effectively ending the war on terror. The externality being experienced here is actually being experienced by the son of the police officer who got caught up writing a ticket to the first man mentioned in this story for polluting (he threw his cigar over the bridge). The officer's son was relying on him to drop off some lunch money at school for him, but due to the man seen throwing a cigar over the bridge, the officer was held up and unable to bring money to his son. The externality here is negative, and it can be internalized (solved) by always remembering not to litter.