# Peter Backus explains 'Why I don't have a girlfriend' - from Warwick Economics Summit 2011

https://www.youtube.com/watch?v=c_jgOzHLIUI
Translation: fr

[00:00] is everyone enjoying the summit so far I

[00:02] just showed up today the organization

[00:05] team's amazing they're so well organized

[00:06] I've never been that well organized for

[00:08] anything in my life that speak is coming

[00:10] out every 20 minutes it's uh it's like a

[00:12] fashion show

[00:14] actually it's very ex there we go yes

[00:16] thank you very much all right so as the

[00:19] Inu said my name is pet bis and I wrote

[00:21] a paper a few years ago called why I

[00:22] don't have a girlfriend an application

[00:24] of the Drake equation to love in the UK

[00:27] um to give you a brief history of this

[00:29] paper because I think it's important to

[00:30] give it a little bit of context um this

[00:32] is Far and Away the most successful

[00:35] thing I have ever written or will ever

[00:37] write in my entire life uh it's been

[00:39] downloaded hundreds of thousands of

[00:41] times and for an academic to have a

[00:42] paper to be downloaded that many times

[00:44] and read that many times it must be

[00:45] something that is profoundly influential

[00:48] and may even lead to a Nobel

[00:50] unfortunately for me this is also the

[00:52] silliest thing I have ever written in my

[00:54] life or will ever write in my life so it

[00:56] has not been that influential but

[00:57] hopefully it's entertainment order to

[00:58] people um uh uh uh the other point is

[01:02] that there's many other examples of this

[01:04] exercise that that exists out there that

[01:06] came to my attention after it got all

[01:08] this this media attention that you can

[01:09] see on my website there some links to

[01:11] various examples of it so with this in

[01:14] mind why I don't have a girlfriend um in

[01:18] 2008 20072 2008 I was experiencing a

[01:21] period in my life that I had called the

[01:22] Great loneliness and in this period I

[01:25] did not have a girlfriend um and and I

[01:28] was reading a book by Carl San and you

[01:30] might say well that might exp you don't

[01:31] have a

[01:32] girlfriend um I was reading a book by

[01:34] Carl San who's a very famous

[01:35] astrophysicist cosmologist uh

[01:37] popularized uh cosmology um for decades

[01:41] and in his book he talked about

[01:42] something called the Drake equation so

[01:44] what is the Drake equation well this is

[01:46] the Drake equation um but what is it

[01:48] actually where does it come from who's

[01:49] it named after well it wasn't developed

[01:51] by Sir Francis Drake nor was it

[01:53] developed by a man Drake from Harry

[01:55] Potter nor was developed by Canadian

[01:57] actor in hip-hop soon to be Legend Drake

[02:01] it was WR by this man Dr Frank Drake now

[02:04] Dr Frank Drake who's also a cosmologist

[02:07] astrophysicist who was interested in the

[02:08] going Zs of the Galaxy and the universe

[02:11] uh and one thing that he was primarily

[02:13] interested in was uh finding one of

[02:15] these in

[02:17] this he wanted to work out the chances

[02:19] of finding that so what he did is he

[02:21] developed the Drake equation now the

[02:22] Drake equation is a very simple equation

[02:24] don't be intimidated by your math it's

[02:26] only one equation that's very simple you

[02:27] simply apply a series of in inly

[02:30] restrictive criteria to a given

[02:31] population and the resulting

[02:33] subpopulation will meet those criteria

[02:35] that youve apply so he first worked out

[02:37] the rate of formation of stars capable

[02:39] of supporting planets the fraction of

[02:41] those stars with planets the average

[02:43] number of those planets that are

[02:44] earthlike so you don't want gous planets

[02:45] like Saturn uh the fraction of earthlike

[02:47] planets that can support any kind of

[02:49] Life fraction of those planets that can

[02:51] support intelligent life the fraction of

[02:53] planets with intell of life that could

[02:54] have TV radio capable of interstellar

[02:56] communication and you get to G which is

[02:59] is the number of intelligent

[03:01] civilizations capable of interstellar uh

[03:04] uh uh communication and you're probably

[03:06] wondering at this point what does this

[03:07] have to do with economics but we'll get

[03:09] to that minute um so what did Dr Drake

[03:12] Find well there's about 300 billion

[03:13] stars in the in the Milky Way galaxy and

[03:16] you predicted there'd be about 10,000

[03:18] communicative civilizations in the Milky

[03:20] Way about a 133 million chance of of

[03:24] finding a communicative uh civilization

[03:26] if you P at random now the bad news

[03:29] about this is the are very slim so the

[03:30] chances of us finding this alien

[03:32] civilization with whom we could

[03:33] communicate are very slim inde however

[03:35] the probability is positive which means

[03:37] there is a chance of finding a community

[03:39] good

[03:40] population now Dr Drake was interested

[03:43] in finding one of these in one of these

[03:45] but I was more interested in finding

[03:46] something much more important finding

[03:48] one of these than

[03:51] that I wanted to work out how many

[03:54] potential girlfriends are there out

[03:56] there uh for

[03:58] me so I need parameterize Dr Drake's uh

[04:02] uh equation rather than G being the

[04:04] number of communicative civilizations G

[04:06] became the number of potential girl

[04:08] friend so I take R mean the rate of

[04:10] formation of human beings in the UK we

[04:13] said that about 150,000 per year we also

[04:16] want the fraction of that population

[04:19] that are women out it may be different

[04:21] in fact one of the other examples of

[04:22] this was written by a uh a PhD in in

[04:26] space mission design in Canada which I

[04:28] think is the coolest PhD anybody could

[04:29] ever had but he's gay and he wrote a

[04:31] very similar paper to this and it's it's

[04:33] sad if you're gay the population is much

[04:35] smaller but for me I'm interested in

[04:37] women so it's about5 of the population

[04:40] now I'm also interested in having

[04:42] somebody that lives in London because I

[04:44] live in London and I want someone to be

[04:45] close to me in part because if she's my

[04:48] girlfriend hopefully I want to spend

[04:49] time with her and in part because if

[04:50] she's closer to me it'll save me on

[04:52] train

[04:53] fair so the proportion of women in the

[04:56] UK that live in London is op three now

[05:09] we can not apply his

[05:12] behavior be Happ about that and AP to

[05:15] any Italians out there I have Italian

[05:16] friends and it's a very sa but age

[05:20] appropriateness is a very important

[05:21] question I don't want someone to Young

[05:24] cuz if they're too young we may get in

[05:25] fights because I don't know who he

[05:28] is or because I don't care about

[05:31] that now alternatively I don't want them

[05:33] to be too old because well I just don't

[05:36] want someone that's too

[05:38] old so let's say I'm interested in women

[05:41] between the age of 24 and 34 and the

[05:43] percent of uh women in London uh with

[05:46] that between AG is

[05:48] about2 now education uh I'm interested

[05:51] in having a girlfriend who has a

[05:52] University degree now people emailed me

[05:55] once I read this paper said oh you're

[05:56] being a LST why do you only want to grow

[05:58] with as G University and I'm not trying

[06:00] to be elitist I know there are many

[06:02] intelligent people that have not gone to

[06:03] University that's all well and good but

[06:05] for me I'm interested someone who has a

[06:06] degree I want someone with whom I can

[06:08] talk about my work sometimes and a bit

[06:09] of formal training will uh ease that

[06:11] process so we all have preferences I

[06:14] just want someone with a degree so I'm

[06:16] not being AR don't be angry we said that

[06:18] about 26 is it now attractiveness the

[06:23] numbers prior to here are objective

[06:25] these are taken from the office of

[06:26] national statistics and these are actual

[06:28] figures these are of women with degrees

[06:30] in London of women in the UK L and so

[06:33] forth this becomes subjective and it's

[06:35] hard to measure this because

[06:36] attractiveness is subjective now I have

[06:39] Angelina J Julie appear not because I

[06:41] find her particularly attractive but to

[06:43] demonstrate the subjectivity and

[06:44] attractiveness now most people would

[06:46] hold her up as this Paragon this ideal

[06:48] of feminine beauty to me Angelina Jolie

[06:50] looks a bit like

[06:53] this so keeping that in mind I'm not

[06:55] interested in just women that are

[06:57] attractive it's important that those

[06:58] women are attractive to me I can

[07:00] recognize that a particular woman is

[07:01] attrative but she may not be ATT so some

[07:03] people say I was being too piggy I don't

[07:04] think I am I said about one in 20 women

[07:06] with University degree between 24 and 34

[07:08] that live in London I will find a

[07:11] pactic oh we also need the length of

[07:13] time because we need to figure out uh

[07:14] the formation of stars or in this case

[07:16] the formation of ladies uh and I'm 32

[07:18] years old and I have not much to say

[07:20] about

[07:21] that we're going to make a quick

[07:23] transition in the Drake equation a quick

[07:25] simplification so what Drake had done he

[07:27] integrated over the r he integrated the

[07:29] rate of formation over the amount of

[07:30] time that stars are being formed work

[07:32] out the number of stars that are out

[07:33] there we're just going to make a simple

[07:35] adjustment and take the population of

[07:37] the UK as of 2007 which was about 60

[07:40] million people and we're going to use

[07:42] that as our base population and apply

[07:43] these restricted increasingly restricted

[07:45] prated to that

[07:46] population so simply plug in our values

[07:49] and we work out that g equals about

[07:51] 10,000 similar to the number of alien

[07:53] civilizations in the Galaxy now you may

[07:56] end this is about to not 7% of the UK oh

[08:01] you may be thinking that's not so bad

[08:04] especially for

[08:06] you 10,000 doesn't seem like a tiny

[08:08] number and uh I might have been booed by

[08:11] that however we're forgetting some very

[08:13] important criteria some very important

[08:14] components to someone who's a potential

[08:17] girlfriend the first one is are they

[08:19] attracted to me okay and of course I

[08:22] don't want just one that I'm attracted

[08:23] you and she's going to be my reference

[08:24] she must be attracted to me and this is

[08:26] going to set at about 05 again 1 and

[08:30] and this is indeed depressingly

[08:33] low I'm also interested in their

[08:35] availability so I don't want to find

[08:37] somebody who's married or has a

[08:39] boyfriend it complicates things uh

[08:42] significantly so I'd like to just have

[08:44] someone who single and available at the

[08:46] time that we meet and we're going to say

[08:48] this is about half now keep in mind this

[08:50] would be decreasing with age as well

[08:51] which can complicate matters if we were

[08:53] that into the

[08:56] model now this issue of compatibility do

[08:59] we get along with one another again it's

[09:01] a subjective measure it's very difficult

[09:03] to quantify on has no statistics on the

[09:05] number of people in the UK I would get

[09:08] along so I carried out some very

[09:10] unscientific research to try to

[09:12] determine the characteristics of

[09:13] individuals with whom I do get along I

[09:15] looked at my friends I looked at family

[09:17] members that I actually like and tried

[09:19] to work out what are the traits that we

[09:20] have in common and came three important

[09:22] factors first if you love ice cream if

[09:26] you think Anchor Man is one of the great

[09:27] artistic achievements of the last

[09:30] and if you think we've all had about

[09:32] enough of Richard Hammond we will

[09:34] probably get

[09:35] along and we're going to set this at

[09:37] about

[09:39] 0.1 so once we've applied all these

[09:42] criteria the objective the subjective

[09:44] which may vary for one person to another

[09:46] I think I've been rather uh uh uh

[09:48] conservative in my estimate but over the

[09:50] 61 million people in the UK how many

[09:52] potential girlfriends are there

[09:56] 26 that's a very small number now this

[09:59] might depress you or it might make you

[10:01] happy it really depends on what you

[10:02] think your chances are were before you

[10:04] saw this

[10:06] presentation so what is the bad news

[10:09] well the bad news from this very simple

[10:11] application of Dr Drake's equation is

[10:13] that taking someone from random at

[10:15] random from the UK the odds of them

[10:17] being a potential girlfriend are about 1

[10:18] and 285,000 is about only 100 times

[10:21] better than finding alien

[10:26] civilizations uh it's also significantly

[10:28] worse for the OD

[10:39] dying now what is the good news about

[10:42] this the good news is that the

[10:43] probability remains

[10:46] positive real friends are not in fact

[10:49] science fiction and indeed shortly after

[10:51] writing this paper I found one

[10:58] [Applause]