What are the advantages and disadvantages of doing a postdoc in Singapore and UK? I am end of my PhD. I would like to do a postdoc. In UK the average postdoc salary is around 30K (per year). But in UK the tax is very high, after taxes I may get around 1800 pounds (per month). I heard in Singapore the salaries for postdoc are a bit high and the taxes are also very low. 

I have my wife and two children, In that case I would like to know the advantages and disadvantages of doing a postdoc in UK or Singapore.
My answer will focus on entirely non-academic aspects of a post-doc in UK as you seem to have those "sorted".

I think you have been slightly mislead:


~£30K will not result to ~£18K after taxes. I was taking ~£31K and ending up with ~£24K. Maybe you are in a different tax-category or something but from ~£30K to end up &lt;£20K is quite unrealistic. Finally, ~£30K with 0 years of experience is pretty decent. One more point: spend an hour or two and check the HM Revenue &amp; Customs. Do not rely on word of mouth on something so vital.
You need to factor council taxes and these will dependent where you live. Council taxes can be quite hefty (£100+ per month in Cambridge for example).
As @John mentioned, you need to base your decision on where are you going to live; ~£30K in central London, Oxford or Cambridge with 2 kids? No way. ~£30K in Manchester or (even cheaper) Coventry? Probably tight but doable.
London allowance have not saved anyone. Sure you will get probably ~12% more than your equivalent post-doc outside London but that's about it. In some cases you can get the same salary outside London. Lesser known universities try to give more monetary incentives to candidates.


I recommend you do some very good research about where exactly you are going, what is the cost of living, what are schools/nurseries are there, etc. Also do maybe a quick online search for houses to see what is available. If the going rate of a two bedroom flat +£1100 well... you need to consider things seriously. And do the same search for Singapore too afterwards!

Post-doc is a stepping stone. Realistically you will not get a salary that will allow you to live a luxurious life. Also take into account that the chances of tenure in an institution after a post-doc while usually better than being a complete outsider are all but guaranteed. Therefore consider that relocation might be something you will have to re-examine. You do not tell us if your wife will be able to contribute to your family income. Even a part-time job might make a significant difference.

(Reading back my answer I think I sound a bit grim... I do not mean to dishearten you or anything, just I do not want to be mislead on taxation or living costs issues.)