This is basically an argument that China should become more like North Korea rather than the other way around.
Reality is that remittances and the skills that emigrants eventually bring back to their home country far exceeds any negative effects. Policymakers know this which is why they don't deter this from happening. In many countries they actively encourage it, such as is Philippines.
When economists talk about "no free lunch" they are specifically talking about abnormal profits. They are not talking about the fact that voluntary decisions of private actors can lead to positive sum outcomes in utility.
Reality is that remittances and the skills that emigrants eventually bring back to their home country far exceeds any negative effects. Policymakers know this which is why they don't deter this from happening. In many countries they actively encourage it, such as is Philippines.
When economists talk about "no free lunch" they are specifically talking about abnormal profits. They are not talking about the fact that voluntary decisions of private actors can lead to positive sum outcomes in utility.