Ah Chai sells chicken rice at a busy hawker centre. For some reason, his stall is very popular. Every day, his stall is surrounded by a long queue of hungry customers.
One morning, Ah Chai had an idea. “For one extra dollar,” he called out, “you may join the Fast Queue and be served first!” A few office workers took the offer, happy to save a minute or two.
Before long, so many people paid the extra dollar that the Fast Queue became as long as the regular one had been. No one wants to join the regular queue anymore.
Ah Chai grinned and announced a new deal. “For two extra dollars, you may jump into the Very Fast Queue!”