Prisoners Dilemma

hi my name is Allen sands and I'm standing outside the BD biodiversity museum at the University of British Columbia welcome to the global politics instructional video series in this series we're looking at a series of questions concepts issues relevant to the study of international relations and global politics and today we are looking at the prisoner's dilemma now prisoner's dilemma is really interesting it's a branch of game theory and game theory has its origins in mathematics and we don't normally associate global politics with mathematics but in this respect it's actually very important what game theory is all about is modeling behavior modeling the behavior of actors individuals groups and States and what we're really interested in with respect to game theory is that what it does is provides us an idea of how decisions by different actors interact with one another the decisions I make along with the decisions someone else makes can actually start to determine outcomes and game theory can model this for us now prisoner's dilemma is a really good example of this and we use it quite a bit in international relations the basic concept of prisoner's dilemma is that it is possible for two actors even if they completely understand what the best outcome for them might be might actually choose a different course of action in other words they might actually choose an action that they know isn't their best option available to them and this gives us some insight as to why for example in global politics we might not have climate change treaty sign we might not have arms control agreements side we might not have trade agreements side it seems to benefit everybody so why aren't we getting these types of outcomes prisoner's dilemma gives us an insight into this question so let's have a look prisoner's dilemma prisoner's dilemma is a two-person game and it describes a situation facing two prisoners captured by the police prisoner a and prisoner B and prisoner a and prisoner B are captured by the police while committing an armed robbery and after they're captured they are placed in separate cells and they cannot communicate with one another now police have insufficient evidence to prosecute both of them for armed robbery and as a result they require a confession from one of them or both of them in order to prosecute for that crime otherwise all they can do is bring weapons possession charges against both prisoners and those charges carry a lesser sentence so the police offer both prisoners a deal this deal creates a dilemma for the prisoners do they trust one another and stay silent and not give the police what they need to prosecute for the crime of armed robbery or do they confess in effect defecting from their cooperation in order to achieve their own personal gains now the whole idea of prisoner's dilemma is that the situation creates pressure on the prisoners to take a course of action that isn't necessarily the best course of action for them and here's what I mean by that so let's start with prisoner a so the police go into prisoner a's cell and they say look we want you to confess to this crime and if you do confess to the crime which carries a sentence of 10 we will let you go free in return for your confession but your partner if they stay silent will then take the entire sentence of 10 years similarly the police go to prisoner B and they basically say the same thing they say look prisoner B if you confess to the crime we will let you go free and if your partner stays silent they will take the full penalty a sentence of 10 years if both prisoners confess the police tell them they will split the sentence and each will go to prison for five years half of the 10-year sentence for armed robbery but remember if both prisoners stay silent the police don't have enough evidence to prosecute them for armed robbery they can only prosecute them for weapons possession charges and those charges would result in a penalty of one year for each prisoner and what this dilemma does it creates a very interesting situation for both prisoner a and prisoner B who remember can't communicate essentially it boils down to trust does prisoner a trust prisoner B enough to stay silent does prisoner B trust prisoner a enough to stay silent because if they both stay silent they will only receive a one-year penalty for both of them but the pressure is on them to confess of course because if they confess and the other doesn't they will go free and their partner prisoner B in this case or prisoner a in this case will take the full 10-year penalty if they both confess they'll split the 10-year penalty so the ideal situation for both prisoners as a partnership the two of them together is to stay silent they'll both incur only a one-year prison sentence but the pressure on them is to confess because the likelihood of one of them confessing and the other not is quite high and in that case if they do not confess and the other does they will spend ten years in prison that's a long time to be in prison whereas if they confess and the other doesn't they'll go free for a year but if they both confess at five years in prison the result is that it's safer to confess there's very possible that by confessing you'll go off scot-free and your partner will get 10 years the worst that can happen is you'll have five years split between the two of you staying silent is the best option for both of them together but the risk of course of staying silent is that your partner confesses your partner defects and you'll be spending 10 years in prison not good so the whole idea of the prisoner's dilemma is it illustrates the difficulty for two partners to stay in cooperation with one another to trust one another and in international relations this idea this game illustrates how difficult it is to maintain a partnership to maintain cooperation because incentive structures may present you with a very real possibility that if you commit to a course of action and someone else doesn't you will incur the full penalty and someone else will benefit okay so that's prisoner's dilemma it's pretty interesting isn't it so the whole idea is that even though two actors might know what the best outcome is they won't necessarily achieve it because there are issues with respect to trust and issues with respect to how their decisions might interact for them in their own futures this is obviously not only relevant to arms races but also it tells us why climate change treaties haven't been signed or haven't been adhered to or why international trade agreements haven't been signed or haven't been respected after they've been signed prisoner's dilemma gives us a really interesting way of explaining many of the outcomes in global politics I hope you enjoyed this video join me again next time

Channel: allensens

Views: 84,901

Rating: 4.8612142 out of 5

Keywords: Clip7, Prisoners, Dilemma, mov, HD

Id: ous1FgCpcW8

Length: 9min 23sec (563 seconds)

Published: Mon Feb 27 2012