Monday, February 13, 2012

Numbers in 2011 - from More or Less podcast

One of my favourite podcasts is BBC's More or Less. At the start of 2012, they did a series on Numbers in 2011. I know it's a little late in sharing this, but here we go - enjoy.

I'm sharing with you a selection of the numbers from the 30min podcast. They are somewhat UK centric, but still worthwhile sharing.

Listen to the whole podcast here.

  1. 80%: developed world's debt to GDP ratio
  2. 1.37: cost of petro in GBP on 9 May 2011 (highest in 2011), due to duty, value added tax (20%) & exchange rate (weaker GBP against USD)
  3. 1%: BBALIBOR (interest to be paid in 3 months time) 10 Nov 2011 crossed 1%, doubling of the bank interest rate. BBALIBOR indicates the risk of money not being paid back in 3 months - a show of lower confidence/trust between banks.
  4. 2.64m: unemployment in UK by December 2011 (highest in 17 years). Note UK population is just over 62m.
  5. 900k: people today working beyond 65 years old in the UK
  6. 12,500: people celebrated their 100's birthday in 2011 in the UK; and will rise to 100,000 over the next 25 years
  7. 7bn: world population
  8. 2.5: average fertility of women on earth (babies per lifetime of earth, falling from 6 from 60 years ago), easing on the environment I suppose
  9. 3,000gbp: cost of sequencing the human genome; in 2003, the first sequencing of human genome cost 600m GBP - that's a 200,000 fold reduction in cost in 8 years
  10. 2 weeks: to sequence 5 human genomes in 2010; in 2003, it took 10 years for one

Tuesday, January 3, 2012

School uniforms in developing countries: An unnecessary evil? - High-level test

Earlier I wrote a post about the requirement for school uniforms in developing countries and how I saw this as a potentially offensive injustice. I completed the first step by forming my hypothesis, "The unnecessary requirement for school uniforms in developing countries puts undue financial stress on families already struggling to afford basic necessities and/or tuition, and potentially even excludes some children from attendance." Now I am looking to test that hypothesis quickly at a high level. I want to do some research to gain reasonable assurance that the hypothesis is correct before I might move on to establish the magnitude of the problem.

Schools for Africa is a UK Registered Charity mainly focused on building schools, but who also say: "£40 will buy 10 sets of primary school uniforms". To put this into perspective:
  • They also say: "£235 will buy 50 text books for the children to share". That's £4.70 per textbook vs. £4.00 per uniform.
  • £4 is about the same as an average day's wages in Ghana
  • £4 is about the same as an average week's wages in Ethiopia
  • I choose these countries as I visited them in 2011, but it is worth noting that Wikipedia reports school uniforms as required in Ghana
The folks at Project Ethiopia, an American 501(c)(3) have reportedly bought 1,695 school uniforms at $8 a piece. These uniforms are also said to last two years, so that's an annual cost of only $4. They make the relevant point that these uniforms are the only set of clothing for many, which would lower the additional burden of the uniform requirement on top of that for clothes. Note, however, that $8 is more than a week's wages as calculated above. Again for perspective:
  • They also claim to buy over library books for $3 a piece
  • They also claim to buy a years school supplies (5 exercise books, 1 pen, bar of soap) for $3
Gift Ethiopia, a UK Charity will provide an Ethiopian school uniform for £8, describing it as such:
Without a uniform, many children in Ethiopia are unable to attend school. Many families, especially larger ones, struggle to provide a uniform for all their children. These children are denied an education and the chance to socialise with children their own age. Your gift will provide a student with a brand new, full school uniform, ensuring they can take their place in the classroom with pride.
  • £8 for a school uniform is about the same as they say it will cost to provide a school dinner for over 10 weeks
The first program listed on the website for Common Threadz, a 501(c)(3) American non-profit, is "School Uniforms for Orphans & Vulnerable Children". They describe the problem:
For families facing the challenges of poverty in Africa, school clothes are not as crucial as the next meal. The direct costs of education, from a uniform and shoes to books and stationery, force millions of orphans and vulnerable children to miss out on school each year. For a child in need from a poor rural family who may only own one pair of old pants or a tattered dress, a school uniform is not just a requirement, but essential to build confidence and academic success.
World Vision UK runs MustHaveGifts, and sells a pretty smart looking Pakistani school uniform for £12.
  • The uniform is described thusly:
    • Pakistan: Children who can't afford a compulsory school uniform can be denied the right to an education, leaving them vulnerable to exploitation. With a school uniform, children can attend school for the very first time and get on the path to a brighter future.
  • At $2,500 USD per capita PPP GDP de-adjusted to remove PPP is $941 or £1.65 per day or almost £12 per week
Based on the above I think that we can conclude that there is reasonable evidence to suggest that in parts of the developing world school uniforms are comparatively expensive and a prerequisite to education.

The next step, though I may not endeavour to take it due to the scale of effort required, is to gather all of the available evidence together to establish a high-level estimate of the scale of the problem. What is the aggregate cost of school uniforms across the developing world? How many children are denied an education as a consequence of their family not being able to afford school uniforms? Ultimately building to the question, What if the requirement were abolished? Once we know the "size of the prize", and please do forgive me for that blatant consultant-ism, we can begin sizing up what can be done about it.

School uniforms in developing countries: An unnecessary evil? - Hypothesis

There are charities helping families in developing countries to buy school uniforms for their children so that they can attend school. This is a good thing, right? Which part? The part about charities helping families in developing countries or the part where this is even a problem? If what I consider to be an arbitrary policy is preventing impoverished children from getting a primary education, this is a great injustice.

Testing this with a few friends, I have concluded that this quite possibly is the case, and I also received some stark warnings about the social, cultural, and psychological dimensions to school uniforms. These warnings are certainly valid, but many great in justices in this world have been toppled that were held up by social, cultural, and psychological factors. The question is, how big is the problem, how big are the barriers, and are our efforts best placed elsewhere?

It occurred to me that this is an opportunity to try out some strategic modelling and analysis, something that I do often in my current work. I have already completed the first step of forming a hypothesis and testing with a few peers. To pursue the problem further I would take the following steps:
  1. Form a hypothesis:
      The unnecessary requirement for school uniforms in developing countries puts undue financial stress on families already struggling to afford basic necessities and/or tuition, and potentially even excludes some children from attendance.
  2. Test hypothesis at a high level
      Gather whatever evidence is at hand or easily available to sense-check and/or refine the hypothesis. Might the hypothesis be true? Is it likely enough to be true enough to warrant further investigation?
  3. Estimate the magnitude of the problem/scale of the potential benefits from taking action
      This will be much like a top-down strategic business case. The key focus will be "What if we could achieve a change?" without yet talking specifically about what actions would be required. Like the previous step, this is another gate we have to pass where we must be certain it is worthwhile proceeding. The output can also be an important number socially, as $x million lost per year or y thousand children excluded from primary education worldwide can be a useful catalyst for change as it is shared and repeated.
  4. Develop a portfolio of initiatives
      Preferably in a brainstorming/facilitated workshop environment, work with stakeholders and subject matter experts to generate potential initiatives or interventions to address the problem.
  5. Prioritize initiatives
      Estimate costs, benefits, and risks of each initiative and then build an action plan, selecting the highest benefit set of activities that fit within your budget or capacity while managing/minimizing risk. This is a classic Operations Research portfolio optimization knapsack problem, though in practice, problem sizes are small mathematics are rarely used.

Friday, December 30, 2011

Operational Research Consulting & Data Journalism

As data becomes more and more accessible, together with visualisation tools becoming more available and user friendly, Data Journalism is heating up. I've been following the Guardian's Data Blog enthusiastically, it is full of interesting information relevant to current affairs, explained with much facts and data.

This article talks about the 10 point guide to data journalism. I particularly like point 5:
Data journalism is 80% perspiration, 10% great idea, 10% output
The Prezi under point 5 explains the process of how data is used to support news, the angles to consider when mashing datasets together, the technical challenges of working with data, iterative calculation and QA process, which finally get turned into the beautiful output with the various (mostly free) visualisation tools.

This is practically the same process that an Operational Research consulting project takes - or any application of OR or Science in general:
  • Understand what the problem/question is
  • Create a hypothesis to be proven or disproved
  • Define what data is needed for the quest
  • Get the data
  • Clean it, and manipulate/wrangle with it so it's usable for analysis
  • Analyse/calculate to come to some conclusion - hence proving or disproving the hypothesis
  • Compare it to subject matter experts' view on what the likely answer should be (sanity check)
  • Refine the analysis until satisfied
  • Shape the output message so it can be easily understood by the audience
  • Communicate the findings
  • All throughout the process, keep communicating to the audience to make sure they are engaged and understand (principle-wise) what you're trying to do, so that they are not unpleasantly surprised when the final answer is presented
  • Best yet, to ensure smooth change management if your solution is to be implemented, work closely with the end users from the start of designing the solution, and then implement and test, so that they believe in the solution because they were part of the creation process.
As the Flowing Data blog points out, this is what statisticians do. I will add that this is what Science does in general. I will also say that in practice, the first step, "understanding what the problem/question is", often takes 70-80% of the time. The technical 'doing' to follow, in practice, is relatively easy compared to what our academic institutions thoroughly prepare us for (which is needed).

For those interested in the how of data journalism, read this about the work that went into reporting on the 2011 London Riots. Fascinating social media analytics at work. Not easy. Impressive and very interdisciplinary.

P.S. Most of this post has been sitting as draft since the summer, hence referencing 'old' news. It's still relevant, so why not.

Sunday, August 14, 2011

Operational Research considered 1 of 6 dsciplines in Social Sciences

Okay, so OR is grouped with Statistics as one of the six disciplines of social sciences, but still, I'm pleasantly surprised that OR is mentioned!

According to QS World University Rankings, the six disciplines considered as part of social sciences are:
  • Finance
  • Economics and Econometrics
  • Law
  • Politics and International Relations
  • Sociology
  • Statistics and Operational Research
Here you can download the full table (yeah, Google Doc!), and see the top 10 universities at a glance for each of the above subjects. For Stats and OR, here are your top 10:

Rank Institution Country
1 Stanford University United States
2 Harvard University United States
3 University of California, Berkeley (UCB) United States
4 University of Cambridge United Kingdom
5 Massachusetts Institute of Technology (MIT) United States
6 University of Oxford United Kingdom
7 National University of Singapore (NUS) Singapore
8 University of Toronto Canada
9 Imperial College London United Kingdom
10 Princeton University United States
P.S. If you haven't discovered it already, the Guardian's Data Blog is great!

Sunday, July 31, 2011

An Alternative Way to Fly (as long as expectations are managed)

The purpose of this post is to share the discovery of an alternative way of operating an airline (flight schedule and route wise).



No matter how airlines degrade their service standards these days in the West, I think it's fair to say that most of us still believe that most airlines *intend* to:
  • Take off on-time
  • Land on-time
  • Fly us from A to B as the ticket says, without surprise stops
  • (Oh, and have toilets, of course)

On a recent trip to Ethiopia, we have been shown a rather different way of operating an airline. It contradicts with all of the above, but it works. We took 4 internal flights.

Here is how we experienced them first hand:
  • 1 left on time as per the ticket, and even got us there early (bonus!), because...
  • None of the 4 flights flew the original path it said it would: stopovers were skipped to go direct instead, or the direct flights got stopovers added onto it last minute
  • None of them arrived late, because...
  • Some of them took off earlier than stated
  • Additionally, the air stewardesses were lovely, and they gave passengers snacks and drinks (*gasp* what novelty!)
  • To their credit, they did try to inform passengers of the changes a couple of days ahead of the flight (in our case by email, which we only read after we got back to London).
  • They also tell passengers to double check the flight times a couple of days before, to be aware of any late changes.
(For your curiosity: the international flights from London to Addis Ababa was quite standard. The only oddity was that they weighed everyone's carry-on luggage at the gate, because it's apparently a popular flight to take lots of stuff with you!)

IMHO, an airline would play this game, because: (we suspect - unconfirmed)
  • It wants to minimise costs - mainly fuel in this case.
  • It has 1-2 planes that fly in circles to cover off a handful of popular destinations.
  • As the airline gets more and more requests for seats through the form of purchased tickets, it is faced with an optimisation problem to fly all its customers to their expressed destinations with minimum cost. The best way to do this is probably through re-shuffling the schedule. For instance, if a plane is hopping from A to B to C in sequence, where B is closer to A than C is, and if we discover 2 days before the flight that the plane is filled with 2/3 passengers going to C, and 1/3 going to B, then flying A->C->B is cheaper than A->B->C. What if there are customers wishing to go from B to C? We hear that the airline is known for cancelling flights as well. Luckily, we didn't experience this.
This way of operating an airline is possible, because:
  • It is a monopoly.
  • The number of flights are few, so it's easy to manage change.
  • Customers expect it and adjust flying behaviour accordingly (i.e. always check the flight times before the day of flight, and always leave wiggle room before and after the flight).
  • For foreigners who are used to the typical western airline service (i.e. expect it to take-off and land on-time and fly the route it says it would), the price justifies it and shuts people up from complaining, and instead people will have a laugh (or write a blog post!) about it.
  • It doesn't call itself "Precision Airline" (the Tanzanian airline), and can afford to deviate a little. 8-)
P.S. If you are planning to visit Ethiopia, and intend to fly within the country, you may want to consider buying the tickets within the country rather than online. It is significantly cheaper due to price control. This is true as of spring 2011, so double check this before you travel.

Monday, March 28, 2011

YoungOR Conference 2011 - Talks in the Consultancy Stream

It's only 1 week away from the YoungOR conference in Nottingham, UK. I am looking forward to chairing the consultancy stream, so I finally get to meet the speakers I worked hard at recruiting.

It will be the busiest the consultancy stream has seen it! We have 2 keynote talks plus 5 titles lined up for the stream over the first 2 days of the conference. The conference schedule is packed, with 5-6 talks to choose from at any time (except for the plenary slots, of course). If you are young to OR, that is 10 years or less in Operational Research, come and check it out.

The Consultancy talks are as follows in chronological order:
  • Keynote: OR Joining Analytics, by Russell Hodge, Capgemini Consulting
  • Revenue Management At British Airways, by Peter Wilson, British Airways
  • Pharmacy Service Cost Inquiry, by Nicholas Jones, PriceWaterhouseCoopers
  • Roundtable Panel Discussion Consultancy on "OR and Enterprise 2.0", "can OR people be leaders or are we destined to be the brains in the back room", and "Who is the boardroom champion for OR". Serving on the panel is a host of talent from various OR consultancies plus an independent, who is also giving a plenary talk at the conference
  • Keynote: An OR Professional On ‘The Apprentice'?, by Dave Buxton, dseConsulting
  • OR Consultancy For The Emergency, by Guy Bickerton and Graham Holland, OR in Health (ORH)
  • Scottish Rugby: Tackling Meaningful Statistics, by Ursula Mulholland, Capgemini Consulting
  • Day In The Life Of An OR Consultant, by James Lally

Also, if you're an experienced conference chair, care to share some of your tips on what to do / not to do, etc.?


Monday, February 28, 2011

85% of Statistics Are Made Up On The Spot

I had a good chuckle the other day when I was caught by an example of numerical illiteracy on the part of at least two people: an author and an editor. I had to share.

I was flying with Air Asia from Banda Aceh, Indonesia to Kuala Lumpur, Malaysia. The in flight magazine isn't exactly high production value, as the airline is all about saving. Consider Air Asia to be the Ryan Air of the East. Anyways, here's the tasty treat now:

I can take no issue with the first section on young billionaires as it was actually quite interesting. In the second section, I am entertained by the translation of $122.1k GDP per capita to an average income of about $120,000 per year. Taking the crown though, was the gem at the bottom.

"72% of the 14.5 million population in Mali, Western Africa, earn about $0.003 a day with the average worker's salary of only US$1,500 per year!" Now what is that supposed to mean?

Before you reach for your calculator I can tell you that $0.003/day = $1.10/year.
Also I can tell you that 72% of 14.5 million = 10.44 million.
And that (10.44 million people * $1.10 per person per year ) / $1,500 per worker per year = 7656 workers.
And that 7656/10.44 million = 0.07% employment.

Curiously I can't quite determine what I think they were going for. Anything I try to explain the numbers I see gets destroyed anyway by the strange "72% of 14.5 million". According to Wikipedia, only 43.51 million out of the 81.76 million people in Germany are employed. I suppose I could say that 53% of Germans earn about $0 per day. By adding a dash of real workers I could make that figure $0.003.

Please comment and speculate.

Sunday, February 27, 2011

Faking It On Your Wedding Day

Earlier this month we wrote about our love of podcasts and just last week I was listening to Japan: A Friend In Need from the BBC Documentaries Archive. Here I was in the month of love, listening to a podcast on the subject and I found math in an unexpected place.

The documentary is about an agency in Japan that supplies fake people, or actors I suppose. In particular, this agency will supply people to fill out your side of a wedding. In the given example, we met a young man whose parents were deceased and his siblings were astranged, such that he only had two friends to attend his wedding. So as to keep up appearances, unbeknownest to the bride, he hired parents, friends and relatives. All told, 30 people at his wedding were fake, costing him something like £3,000, equal to his recent redundancy compensation.

The agency claims never to have been caught, and they say that they "research their assignments assiduously", but it got me wondering just how long you could operate such a service without getting caught. How many weddings could you do before a repeat guest noticed that they had seen one of your actors at a wedding before?

The first wedding is simple, and guaranteed to go off without a hitch, but what about the second? Suppose every wedding has on average 30 guests from each family. In the second wedding we need all 30 people to not be from the 30 in the previous wedding. Still pretty easy in a country of 127 million. But what about the 30th wedding when there are 900 previous guests out there in the population? Things are still looking pretty good, but the probabilities are starting to pile up in a similar way to the phenomenon that means that in a group of 23 people there's a 50% chance that two will have the same birthday.

So given a constant wedding size of 60, 30 real and 30 fake, what is the probability that this is the wedding that breaks us? This is the same as the probability that one or more of today's guests attended a previous wedding. This is the same as one minus the probability that none of today's guests attended a previous wedding. For wedding n and a population p:
Assuming 127 million people in Japan...
  • For wedding 1, it's a sure bet as nobody has attended a previous wedding.
  • For wedding 2, we face only a 0.0011% chance of getting caught.
  • Even for wedding 100 our risk is only a 0.11% chance. No problem!
But wait, the above probabilities are conditional probabilites. Our chance of getting caught at wedding 100 given that we got to wedding 99 is 0.11%. What is our chance of getting to wedding 99? This is the the probability that we didn't get caught in one or more of the previous weddings, the probability of a perfect record. Mathematically our chance of getting to and past wedding n is:
  • For wedding 1, it's a sure bet.
  • For wedding 2, it's 99.99%
  • For wedding 100, it's 94.58%.
  • For wedding 500, it's 24.57%.
Even though by the time we get to wedding 500, ony 15,000 people in Japan have been to weddings with our staff, we would be lucky to have made it that far.

If we started this agency today, on average how long can we expect to go before we get caught? Now I'm not going to bother expressing that mathematically, but hacking at it with Excel numerically, I can tell you that it comes to roughly 374. If we were to start such an agency today under such conditions and such assumptions, we would on average expect to do 374 weddings before getting caught.

So I think the moral of the story is, if you're looking to hire fake people for your wedding, you're doing alright, but if you're looking to run a business doing it, you might want to reconsider. Then again, if we're looking for morals in this story, honesty might come first.

Monday, February 7, 2011

I heart smartphones and podcast favourites

I heart smartphones. It is the symbol of the new world, where the world is at your finger tips, and, in your pocket! There is so much information out there, digesting it is a big quest. I'd love to have the time to sit down and browse the net for a couple hours every day to catch up on all the news and events, but now I can do all this while on the move.



I am an owner of an HTC Hero on Android. It is the only digital device I carry in my hand bag (other than my obligatory work phone). Living in a busy city like London means I spend a fair amount of time in transit. If you are a Google fan like me, then Google Reader and Google Listen would be your good friends. My favourite activity during transit when I'm not walking about, is to catch up on the news and my favourite blogs through the RSS reader. My favourite activity during transit when I am walking about, is to plug into one of the following podcasts, which keeps me informed and entertained. If this is not optimising your time, then I don't know what would. I guess the next step is to jog to work while listening to podcasts: information downloading and calorie offloading all at once!

  • LSE lecture and events: London School of Economist half hour to hour long lectures or guest speakers plus Q&A session (frequent publishing of events)

  • The Economist: I like the magazine, but there is so much content to digest. The podcasts do a great job summarising the highlights (weekly publishing or more frequent ones available too)

  • NPR News: short bursts of news that keeps me informed of the North American highlights (hourly publishing)

  • Science of Better: Operations Research podcasts/interviews by INFORMS (monthly publishing)

  • More or Less: BBC radio programme making sense or debunking the numbers behind the news

  • Freakonomics: spin off by the authors of the ever so popular Freakonomics book/movie/blog/etc.

What are some of your favourite podcasts?


Aside from being my RSS reader and podcast player, my smartphone is also my:
- phone (first and foremost)
- email
- calendar
- access to the internet
- Skype to call anyone around the world
- instant messaging to keep in touch with friends
- handy document storage
- camera / video cam
- GPS and compass
- maps (offline maps too)
- ebook reader
- notebook (takes my hand scribbling too)
- news reader
- scanner
- games when I'm bored waiting in a queue somewhere
- MP3 player
- all the other things that come with a phone (alarm clock, calculator, voice recorder, etc.)
- and thousands of other applications available for download (often for free) that keep my life organised and what not