The Bank of England has a new paper out titled The impact of immigration on occupational wages: evidence from Britain. Its key finding is that “the immigrant to native ratio has a small negative impact on average British wages…Our results also reveal that the biggest impact of immigration on wages is within the semi/unskilled services occupational group.”
Why, then, does the Bank of England correctly state that “There seems to be a broad consensus among academics that the share of immigrants in the workforce has little or no effect on native wages”? The reason is that “These studies typically have not refined their analysis by breaking it down into different occupational groups”, which the Bank’s paper does.
To de-jargon this, studies which find no effect of immigration on wages make no distinction between the wages and workers they are examining; they lump the falling wages of nine road sweepers in with the rising wage of one City banker and say that, on averages, the ten workers wages haven’t fallen. A paper from Oxford University which also dug down into the averages found similar results to the Bank of England; immigration disproportionately reduces wages at the bottom end of the labour market.
In the short run at least, this is what economic theory would lead you to expect. If you increase the supply of anything relative to the demand for it, ceteris paribus, the price of that thing, whether it is shoes or labour, will fall.
But that, too, is to fall into the trap of looking at ‘the average’. There is no labour market in which we are all willing sellers of homogeneous labour. I am not offering the same skills on the job market as Sergio Aguero or Stephen Hawking. The market for the labour of economists and the market for the labour of footballers are different markets, they are not part of ‘the’ labour market. Labour, like capital, is heterogeneous.
To simplify, consider an economy with two types of worker, highly skilled and lower skilled. The markets for each are shown below, for highly skilled labour in chart a and lower skilled labour in chart b.
Immigration of lower skilled workers increases the supply of lower skilled labour – the rightward shift of the supply curve on chart b from S1 to S2. Ceteris paribus, this pushes wages for lower skilled workers down from P1 to P2. But, and this is the point the Bank of England paper makes empirically, this has no effect on the wages of highly skilled workers, as shown on chart a.
If the immigrants were skilled then the opposite would be the case. The wages of highly skilled workers would fall and those of lower skilled workers would be unaffected. It is doubtful, however, that this is currently the case, at least in Britain.
This debate over the effects of immigration on wages, in the short run it should be stressed, is another example of the difficulties economists can find themselves in when thinking of lumpy, homogeneous aggregates. Lumping all labour together for anayltical purposes makes no more sense than, for example, lumping all capital goods together. The Bank of England’s new paper is a welcome step towards greater acknowledgment of the heterogeneity of economic variables.