I am Zhang Jingwen from ECON1001A, I am a little confused about the meaning of need and want, can you explain it to me in detail. and have the following sum as an example:

Higher education is a ________ and assigned textbooks are ________.
need; needs YES
want; wants
need; wants
want; needs
want; needs only if attending school. NO

Thank you very much.

Best regards,
Zhang Jingwen

The difference between need and want is subtle. Page 127-128 of the book contains an explanation. The following paragraph in page 127 illustrate very well:

Economist like to emphasize that once we have achieved bare subsistence levels of consumption [i.e., needs] -- the amount of food, shelter, and clothing required to maintain our health -- we can abandon all reference to need and speak only in terms of wants.

In other words, needs are basic (something you must have to survive to do well), wants are additional. Note that what is need in one society can be want in another.

That is why I do not like the questions you sent over. The answer varies from country to country. The suggested answer may be right for US students, need not be right for Hong Kong or mainland students.

Ka-fu

Subject: Re: asking a question
Date: Wednesday, November 22, 2006 11:55a.m.

Dear Dr Wong,

Thank you very much for your explanation.

I have some more questions on more chapter exercises and I want to seek for some of your advice on the world wide exchange programme.

Can I visit you somethime this Thursday or Friday afternoon. It will probably take less than one hour.

Thanks,
Zhang Jingwen

Subject: Re: asking a question
Date: Wednesday, November 22, 2006 11:59a.m.

Dear Jingwen:

How about Thursday after 3:00p.m. in my office (KKL 1002)? Please tell me the specific time you would want to see me.

Ka-fu

Subject: Re: asking a question
Date: Wednesday, November 22, 2006 4:58p.m.

Dear Dr Wong,

I would like to make it 4:00pm tomorrow.

Thanks,
Zhang Jingwen

Subject: Re: asking a question
Date: Wednesday, November 22, 2006 8:59p.m.

See you then.

Ka-fu

Subject: ppt on the law of iterated expectation
Date: Saturday, March 3, 2007 1:00a.m.

Dear Prof. Wong,

My name is Zhang Jingwen, the student who asked you about the iterated expectations and I now understand how the iterated expectations are solved and the attachment is the ppt I made with an simple example created.

Some of the characters may be used wrong or hard to understand but I have tried my best to make them easy to understand.

Lastly, I want to make sure that is this presentation given by you or me?

Thank you for your explanation on the question,

best regards,

Zhang Jingwen
[Attachment: presentationofecon1003.ppt]

Subject: Re: ppt on the law of iterated expectation
Date: Saturday, March 3, 2007 12:46p.m.

Jingwen:

Great. On a cusory reading, I believe that you have a slight mis-understanding of conditional expectation.

I will talk about it in class on Tuesday. That is, you will not need to do any presentation.

May I know whether preparing the ppt improve your understanding of the concept or not? Will the requirement (for students to write up a ppt after they raise a question) deter you from asking questions in the future?

Ka-fu

Subject: Re: ppt on the law of iterated expectation
Date: Saturday, March 3, 2007 9:00p.m.

Dear Prof. Wong,

I think the requirement of doing the ppt is really helpful for understanding the hard concepts.

Secondly, I would like to ask you questions because I believe you would give me the best solution. And creating examples by myself is the best way to understand the concept but it sometimes cost so much time that we don't want to do it.

So I would like to thank you for the requirement which is the motivation for me to creat my own example. And I will still ask questions in the future but on the condition that I couldn't solve it myself first. In fact, I suggest you in the future give students assignments like creating an example and solve it, which will benefit most students.

Lastly, according to my microeconomics course experience with you as the teacher last semester, I really respect your way of teaching and think you are a really good teacher. I think I am really learning the way to learn.

best regards,
Zhang Jingwen

Subject: Re: ppt on the law of iterated expectation
Date: Sunday, March 4, 2007 11:28a.m.

Many thanks for your encouragement.

For me, teaching is supposed to be enjoyable. I would not be able to enjoy it unless my students can have an enjoyable and fruitful learning experience. It takes both good teacher and good students to create a good learning experience.

I am glad that I have students like you in my class. You have a very good learning attitude. The fact that you appreciate my teaching is a great encouragement to me.

Thanks.

Ka-fu
[The final ppt on iterated expectation (reflecting a joint effort of Ka-fu WONG and Jingwen ZHANG): supplement3.ppt]

Epilogue

Jingwen was the first student I requested to write a Powerpoint (ppt) slides after a discussion with me. Due to the encouraging experience with Jingwen, I have started to request all other students to do the same. Her classmates and the next generations at The University of Hong Kong will benefit:

1. Requiring a student to write up ppt slides after the discussion helps to make sure that the student actually understand the concepts.
2. The ppt slides are written by students and are usually more user-friendly to other students.
3. With some modification, the ppt slides may be used in teaching, thus benefiting other students while saving the teacher's time.