disclaimer: Reviews on paultan.org does not necessarily reflect the views of this blog owner. Sunny Tan does not know Paul Tan. These two individuals just share the same surname, like how Sunny Tan and Vincent Tan of Berjaya Group share the same surname 'Tan' .

The two envelopes problem is a puzzle or paradox within the subjectivistic interpretation of probability theory; more specifically within Bayesian decision theory. This is still an open problem among the subjectivists as no consensus has been reached yet.

The puzzle: Let's say you are given two indistinguishable envelopes, each of which contains a positive sum of money. One envelope contains twice as much as the other. You may pick one envelope and keep whatever amount it contains. You pick one envelope at random but before you open it you're offered the possibility to take the other envelope instead.

Now, suppose you reason as follows:

1. I denote by A the amount in my selected envelope
2. The probability that A is the smaller amount is 1/2, and that it's the larger also 1/2
3. The other envelope may contain either 2A or A/2
4. If A is the smaller amount the other envelope contains 2A
5. If A is the larger amount the other envelope contains A/2
6. Thus, the other envelope contains 2A with probability 1/2 and A/2 with probability 1/2
7. So the expected value of the money in the other envelope is
   
   (note: "expected value" is summation of all possible outcomes times the probability of that outcome occuring. So above, 2A occurs 1/2 of the time and A/2 occurs also 1/2 of the time. Add 1/2 times 2A and 1/2 times A/2, you get 5/4 A)
   
   
8. This is greater than A, so I gain on average by swapping
9. After the switch I can denote that content B and reason in exactly the same manner as above
10. I will conclude that the most rational thing to do is to swap back again
11. To be rational I will thus end up swapping envelopes indefinitely
12. As it seems more rational to open just any envelope than to swap indefinitely we have a contradiction

The puzzle is to find the flaw in the very compelling line of reasoning above.

Thats about it from trusty ol wikipedia....

Now. there are many solutions offered, and many are quite complicated....if you are interested, you can read it up from here.

- paradoxes are everywhere.....the truth is out there... (mayb u can start searching in wikipedia)

The money’s good, but family suffers

 

THEY make good money in Singapore. But for many of the thousands of Malaysians working across the Causeway, it is a great strain on their family life.

The problem came into sharp focus in the recent murder of child kidnap victim, Lo Ching Poon.
The victim’s mother was lonely and depressed raising her four children because her husband was consumed by his work in Singapore.
Consequently, Lee Choon Huay, 33, turned to making friends through the short messaging service (SMS).
Apparently, she had 500 such acquaintances, one of whom is now the key suspect in the abduction and killing of her eight-year-old daughter.

Consultant psychiatrist Dr Benjamin Chan says the episode underlines the pressures on family life faced by Malaysians who commute to work in Singapore daily.
"They are so tired by the time they return home that they have virtually no time for their spouse or children.
"Even on weekends or public holidays, they are so exhausted mentally, emotionally and physically, that what they want to do is sleep," he says.
"Consequently, there is no intimacy in their marriage and this ruins relationships. I am seeing such cases more and more often."

The irony is that most work in Singapore to provide a better life for their families.

 

Take factory worker Tan Geok Huay, 33. This permanent night-shift worker, who earns S$1,500 (RM3,300) a month, even sacrifices her days off and public holidays to work for double or triple pay.
Her husband, Loh Boon Hui, 35, is no different. The shipyard worker leaves for work in Singapore at 5am and often gets home past 9pm.
Their two children, aged 8 and 10, are in the care of Loh’s parents in Negri Sembilan.
Tan and Loh, among the 100,000 Malaysians who commute to work in Singapore daily, send money regularly but don’t get to see the children.

Construction worker Mat Hussin, 36, of Batu Pahat, has three children aged 10 to 15.
Renting a room in Taman Universiti in Johor Baru, he works six days a week with overtime almost every day.
He confesses that he has absolutely no life as he leaves home for work at 6am and returns home after 10pm.
"My wife keeps nagging me to return home every weekend. But I am too tired for that. I usually go home once a month and even then it’s a day trip. I feel sorry for her. But I try to make it up by sending her no less than RM2,500 every month. It is a lonely life."

 

Counsellor Tan Chee Siang says most are torn between family and material needs.
"This is a common pheno- menon in most border towns. It boils down to priorities.
"Do you value money and material comforts more than your family? It is very difficult to strike a balance. That is why some suffer from guilt although their pockets are full of cash."
Children, deprived of love and affection, are the ultimate casualties.

 

Youth worker Michael Moorthy, who is also president of the Boys’ Brigade in Malay- sia, has encountered many such cases.
"In the absence of their parents, they hang out in shopping centres, mix with bad hats and seek refuge in the company of secret societies that claim to care for them.
"By the time their parents realise this, these kids have been transformed and have totally different personalities. It is already too late," he says.

 

Like his parents, high school student Albert Chung, 18, travels to Singapore daily, but they enter the republic separately.
Chung wakes up at 4am to catch the 5am school bus. He is normally back in Johor Baru after 4pm. His parents never cook, so he eats out. By the time he goes to bed, they are still not back from work.
"It is terribly lonely. I am alone most of the time. I make my own decisions. There is no one to talk to or consult.
"Although I stay with my parents, I only see them and have tea with them during the weekends. Even then, they inevitably end up quarrelling."

 

Dr Chan, a member of the board of directors of the Mental Health Foundation, suggests the Government initiate a study on the psychosocial needs of these people.
"This is a valuable group of human resource. It is critical that we reach out to them with special programmes.
"It is also imperative that they remain physically and mentally healthy," he says.

 

Article by Sim Bak Heng, www.nst.com.my , 11th June 2006