Epidemics and advertising

I first learnt the power of stochastic models when I had lectures by the late Professor David Kendall (famed for the Kendall notation for queue models http://en.wikipedia.org/wiki/Kendall%27s_notation). He spoke about a simple model of an epidemic, and how that model gave rise to a statistical distribution for the number of people who would be infected. To add variety to his lectures, he spoke of the way that the model could be modified to describe the spread of a rumour (when someone spreads the message to someone who has already heard it, he realises it is a rumour and stops spreading it).

(Incidentally, I wonder whether David Kendall and I come from the same branch of the Kendall family, as my mother was a Kendall before she married.)

Since then, models of epidemics have become very much more sophisticated, but the essentials remain the same. As I write, the UK government is concerned with the spread of influenza in the population. The Labour opposition claims that the advertising about risk should have been started much earlier. In response, the government have spoken about the need to time the adverts for greatest effectiveness. I suspect that there are O.R. models in the background.

Advertising too long in advance is of limited value -- it will be forgotten. It needs to be at a time when it may affect the behaviour of people, who may be infected or susceptible. So the timing needs to be linked to models of the spread of the current 'flu virus. Hence two models need to be linked -- one about the effectiveness of advertising, the other an epidemiological one. But these models are bound to be in the background and, once again, O.R. is the "hidden science".

When should one use O.R.?

Last week I had to go up to London (why is it always "up to London"?) for a meeting. Three and a half hours in a train to get there, three hours back, and two hours in the meeting. Every time I visit the capital, I am struck by the differences between Exeter (population 110,000) and London (population 7.5 million). This time my attention was caught by the advertisements on the London Underground (OK, I should get a life!). Several stations now have adverts projected across the tracks. But, the advert which caught my eye was on the walls of the escalators, where flat panel screens have replaced some of the static adverts. The advert was for T-mobile, and featured the company's recent TV advert, of a pre-arranged, choreographed flash-dance at Liverpool Station. "Life is for sharing" was the punch line.

Back home, I found the advert in full on Youtube, and also the director's background story behind an amusing and challenging project. Having enjoyed them both, I wondered whether there would be any place in the making of the advert for O.R.. How could "The Science of Better" make the production "Better"?

I suppose that the main traditional O.R. techniques that could have been used would be forecasting and scheduling. Forecasting to make sure that there were enough resources at the right time and the right place. Scheduling to make sure that resources were used as well as they could be. But there is actually little incentive to use O.R. in such a project. Either the people were ready for the advert on the morning of January 15th 2009, or they were not. There's no 95% confidence. It is a one-off event. And there is probably the answer. The director and his team worked to a deadline, made decisions as they were necessary and used a great deal of experience and common sense. And it worked.

Maybe if the director had to make such a film every two months for the next two or three years, then there would be a place for analysis and improvement, but that is not how the advertising world works. Perhaps an analyst can offer suggestions for improvements next time ....

And the other problem with the idea of scheduling is that you are dealing with people. It is often said that many O.R. techniques work better with machines and inanimate objects than when people interact!