The joys and sorrows of two-way ratings systems

‘J’ai failli attendre’ — ‘I almost had to wait’ — allegedly said by Louis XIV when his carriage drew up just a few seconds before he reached the bottom of the palace steps.

Pathetic, I know, but I try to re-enact this moment with taxi booking apps: I watch the car approach on the map on my phone, then time my departure to emerge from the building exactly when the car pulls up at the kerb. It is a moment of synchronicity which delights the trivial mind — in the way many men enjoy timing the flushing of a lavatory so that the end of the flush coincides with the last moment of micturition.

But there is now another reason to do this: to avoid keeping the driver waiting. You may not know, but when you use services such as Uber or Hailo, not only do you get to rate the driver but the driver rates you. Once you learn this, it subtly changes your behaviour: I once found myself telling my children, ‘Hurry up and get in the car. I don’t want to drop below a 4.8.’

In what is known as a two-sided market (such as Uber, eBay or Airbnb) this two-way rating makes sense. With Uber ratings, the lowest-rated drivers are taken out of circulation, and the worst passengers presumably find it hard to get a taxi on a Friday night, thus purging the market of unscrupulous actors. (Uber drivers tell me that they do not usually refuse to pick up poorly rated passengers, but they do sometimes phone beforehand with a contrived query to check they aren’t drunk.)

At its best, the two-way rating system is a mechanism for creating trust by giving participants in a transaction ‘something to lose’ if the other party ends up unsatisfied.