## Wednesday, 11 November 2009

### Show me the money

Just a note to explain how I model the cost of Translink’s delays. Rather than use the NI Civil Service costing model for my grade, which involves a lot of other factors as well as staff salary multiplied by time, I decided to use the average wage x time wasted. I am using median UK wage (currently £20,801), rather than the mean: http://news.bbc.co.uk/1/hi/8151355.stm

This will allow me, at some later stage, by counting passengers, to estimate the value of a whole train-full of us being delayed. I’ll save that for a journey where I’m actually stuck on a train long enough to count all the passengers. I’m sure the chance will present itself if I wait patiently enough!

So here’s how I calculated Monday’s estimate:

1. The average salary is £20,801 for the year (or 52 weeks), but I’m interested in the ‘minutes at my desk’ value of my time.

2. The salary is only based on an average attendance at work of about 43 weeks:

52

– 25 days annual leave (i.e 5 working weeks)

– 10 days public holiday (i.e 2 working weeks)

– around 10 days sick (i.e 2 working weeks)

= 43 ‘commuting into work on public transport’ working weeks

3. So, 43 weeks at 37.5 hours per week = 1612.5 working hours. Therefore, average pay per hour worked, as seen from the employer’s perspective, is around £12.90. This represents how much your time at your desk costs your employer, per hour, on average.

4. Per minute this is about 21.5p

5. On Monday, when I was delayed by 28 minutes, somebody lost £6.02. Either me or my employer. Who loses depends on whether you have to stay late to make up for the lost time (e.g. under a Flexible Working Hours system) or not. All I’m measuring is potentially productive time lost as a result of Translink delays, not who lost it, that’s too tricky for a non-economist like me!

[Note: this is a crude average calculation; some of us take less sick leave, but have more annual leave, or higher salaries. This is just an indicative measure of the value of our time when at work, not taking into account harder to define benefits like staff being more productive.]