1 Which Lift Are You Willing to Wait for? Edward (LI, Xiaoyang)

2 Can you get into the lift? Haking Wong Podium Haking Wong Podium Knowles Building Knowles Building …

3 If I tell you… You can probably save more time! You can probably save more time! Choose the lift on the other side of the building. Choose the lift on the other side of the building. Would you try? Would you try? Keep your answer. Keep your answer.

4 Lift 1 t 1 = 2min Lift 2 t 2 = 1min (few people waiting there) Walk from Lift 1 to Lift 2 t 3 = 1/3min You are willing to pay $3 for the saving of each minute. You are willing to pay $6 to avoid walking up stairs. Let’s suppose:

5 You assume that you will find few people waiting for Lift 2: Cost = (1/3+1)*3= $4 Benefit = $6 Economic Surplus = 6-4 = $2 A good choice to go to Lift 2!

6 You assume that you will only to find as many people waiting for Lift 2 as for Lift 1: Cost = (1/3+2)*3= $7 Benefit = $6 Economic Surplus = 6-7 = -$1 You made a bad decision!

7 According to our analysis, people would not have obvious preference on whether to go to Lift 2. But actually, there are much fewer people or even no people waiting for Lift 2. According to our analysis, people would not have obvious preference on whether to go to Lift 2. But actually, there are much fewer people or even no people waiting for Lift 2. What ’ s wrong? What ’ s wrong?

8 There are other costs! People don ’ t want to be alone or to be thought so by others. People don ’ t want to be alone or to be thought so by others. People can talk with their friends when waiting the lift. People can talk with their friends when waiting the lift. People who carry heavy bags feel really tired to walk any further. People who carry heavy bags feel really tired to walk any further.

9 Revised model: Cost = (1/3+1)*3+3= $7 Benefit = $6 Economic Surplus = 6-7 = -$1 You should not go to wait for Lift 2! The cost of being alone, giving up talking with friends or carrying heavy bags!

10 The revised model suggest that even waiting for Lift 2 can save your time, you would not prefer to waiting for Lift 2! Now would you answer me the question: Will you try to go to the other side of the building to take the lift?

11 Thank you for you attention! Edward Nov. 2006