When you get into a taxi, there’s usually a framed sheet of paper describing what you pay for your trip: the cost of every mile travelled at different times of day, and the price of waiting time.
As digital screens become ever cheaper, it won’t be long before someone suggests that there is no need to have these things any more. Instead a button will appear on the taxi’s new seatback touchscreen which will reveal the tariff when pressed.
All very sensible, you may think. Except for this. The nature of a promise displayed on paper is subtly different to a promise displayed on a screen. Anything writ in liquid crystal should always be viewed with a little added suspicion.
There is a reason why we use phrases such as ‘tablets of stone’ to refer to promises. It isn’t only that stonework endures; once carved, it is also very difficult to edit. And when a declaration is carved in a public place, the reader can see that the promise you are making to him is the same one you have made to everyone else. Public promises carry more weight: hence why the words ‘as seen on TV’ are more convincing than ‘as seen on Facebook’.
But when your taxi displays the prices on a digital screen, you have no way of knowing whether it is displaying ‘the true price’ or ‘the drunk gringo tourist price’. For all you know the driver may have pushed a button under his seat, hiking the tariff according to how much he can gouge from you. Similarly when you visit a travel website using an expensive laptop computer, you may not be quoted higher prices — but by default the website will automatically display a swankier (and pricier) range of hotels.
Today, when your political party makes a promise to you via some highly targeted social media campaign, can you be really sure it is seriously committed to the issue at hand? Perhaps some algorithm simply identified you as one of a number of people in marginal constituencies who care disproportionately about the subject….