Initially, the author's conclusion goes beyond the evidence. The argument assumes, without proof, that the inflow of immigrant workers are the cause of the decline in the average compensation of unskilled labor. It can be noted that there is no information either about the kind of jobs that the immigrant workers do or about the wages that they receive. While it can be true that the immigrant workers may be hired as unskilled workers it is surely wrong to assume that all of them are hired to do low skill tasks. For instance, the immigrant workers may be hired to assume leading positions such as CEO.
Moreover, the argument presupposes that a moratorium on further immigration would cast this kind of problem. However, it is not guaranteed that this action would really help. For example, the immigrant workers may be needed, because the local workers may not want to do unskilled jobs that are necessary for the good health of local economy.
Furthermore, the argument is unconvincing as it stands, for it implies that the downward pressure on wages is caused by the immigration of workers and neglects the fact that the economy may be passing through difficulties caused by other factors.
Consequently, the conclusion does not follow logically from the premises. Several key factors left unmentioned weaken the reasoning described and cannot, therefore, substantiate the argument. Based on the discussion presented above, the argument would be logically convincing if there were presented facts that show that immigrant workers work for less money than local workers and are assigned to unskilled tasks, and that the health of the