Every year, domestic helpers in Hong Kong send money home to support their families. In this post, I want to briefly examine the economics of these remittances. (This post is motivated by this story about the remittances of polish truck drivers from the UK).
First, how large are the remittances? We can get some idea from looking at the level of "current transfers" in the Balance of Payments. For 2006, outflows were 24.6 billion. This is an upper bound on remittances, since it includes all flows of money that are not in exchange for goods and services, such as donations. Still, that's about 1.6% of GDP- a non-trivial sum by any measure.
So what's the effect of this outflow? Conventional wisdom is that this is a drain on the HK economy. But as is often the case with economics, the conventional wisdom is wrong. In order to remit finances home, the HKD earned in Hong Kong must be converted to some other currency. But there has to be a counter-party to that transaction: for every seller of HKD in exchange for Philippines Pesos, there's a buyer of HKD who wishes to sell Philippines Pesos. And why would someone want to buy HKD? In order to buy goods, services, assets, or some other item of value denominated in HKD.
So the bottom line is that there is no drain. This is simply a result of the Balance of Payments being zero- outflows must be matched with inflows.
But there are exceptions to this argument. What if the remittance is made in terms of HKD banknotes? If those bank notes are eventually spent in Hong Kong, then we return to the above case. And if they are not spent in Hong Kong (i.e. circulate elsewhere, or are stored in a safe somewhere), things are even better for Hong Kong. The Hong Kong economy benefits from the services of a worker in Hong Kong, and in exchange the worker contributes 100% of their earnings to Hong Kong's official foreign reserves.
Let me explain. When bank notes are issued, every 7.8HKD issued must be backed by a 1USD increase in the exchange fund. So additional banknotes result in the following transaction: the bank "sells" you banknotes (against your bank balance, say), and in exchange "buys" those banknotes from the exchange fund with USD. With the exchange rate fixed, this has negligible effect on the net wealth of the bank, but leaves you with your bank notes and the exchange fund with larger USD reserves.
If bank notes now leave Hong Kong, then approximately the same quantity of additional bank notes will be required to meet demand. So the reserves increase further by approximately the amount of the remittances. And the HK economy continues to benefit from the accumulated exchange fund balance in the form of interest income from the USD assets in the exchange fund.
If we did not have a currency board in HK, then bank notes circulating outside of HK would be similar to the example in the link above: effectively, the Hong Kong economy would have benefitted from the labour of a domestic helper in exchange for some pieces of paper that can be printed for a few cents each. This may be a trivial source of wealth for a place like Hong Kong, but it provides the United States with a windfall of 20-30 billion USD every year!