The impact of immigration on employment and wages of domestic workers is a long-standing debate among labour economists. In an influential study, David Card collected data on employment and wages of domestic workers before and after the Mariel boatlift - a large inflow of Cuban immigrants into Miami between April and September of 1980 which increased the Miami labour force by 7% - for workers in Miami and 4 comparable cities that did not experience a similar immigration wave.

(a)As a labour economist, what would your prior beliefs be about the impact of immigration on the labour market outcomes for natives in the short-run and in the long-run?

(b)Consider the following table from Card's study. Discuss these estimates. Under what assumptions are they informative about the causal impact of immigration? Are these results in line with your answer to (a)?

Table from Card's study: https://ibb.co/ZTg8gLW