Migrant Networks and Trade: The Vietnamese Boat People as a Natural Experiment
利用越南船民外生分配到美国各州的自然实验，发现20年前接收更多难民的外，在1994年对越贸易解禁后对越出口更多元、份额更高，证明移民网络促进贸易。
We provide cogent evidence for the causal pro-trade effect of migrants and in doing so establish an important link between migrant networks and long-run economic development. To this end, we exploit a unique event in human history, the exodus of the Vietnamese Boat People to the US. This episode represents an ideal natural experiment as the large immigration shock, the first wave of which comprised refugees exogenously allocated across the US, occurred over a twenty-year period during which time the US imposed a complete trade embargo on Vietnam. Following the lifting of trade restrictions in 1994, the share of US exports going to Vietnam was higher and more diversified in those US States with larger Vietnamese populations, themselves the result of larger refugee inflows 20 years earlier.