The report on the economic impact of immigration (PDF format, 1.2MB, on the Parliament website) from the House of Lords Select Committee on Economic Affairs weighs up existing evidence from a wide range of sources.

These sources include 2007 research (PDF format, 630K, external website) from the Low Pay Commission (LPC), which puts forward a formula for calculating the effect of immigration on earnings. The LPC suggests that with every 1% increase in the ratio of immigrants to natives in the working age population:

· wages paid to the lowest 10% of wage earners (the bottom decile) decrease by 0.5%;

· wages at the median or midpoint in the range increase by 0.6%; and

· wages for the highest-earning 10% (the top decile) increase by 0.4%.

The House of Lords report notes that "these effects are fairly modest", but cautions that the data relate to the period 1997 to 2005, and therefore do not reflect the increasing rates of immigration seen in recent years.

But sadly, the conclusion reached by authors of the LPC research would appear to remain all too true: "Immigrants appear to be most concentrated at precisely the same points where we find the most negative wage effects."

As noted in our recent feature (subscription required), there is now a growing body of evidence that migrants are under-utilised in the UK economy.

Indeed, in the same week as the Lords report was published, the TUC launched its Vulnerable Workers project to provide training and employment rights information for Polish immigrants working in cleaning, security and building services roles in the City of London and surrounding areas. TUC research finds that Polish workers comprise two-thirds (65%) of nationals from the eight accession states (A8) that joined the EU in 2004 now working in Britain. Yet they are among the lowest-earning workers in the capital, with three-quarters (75%) earning between £4.52 and £5.99 per hour. One in four (25%) does not have a written contract of employment.

· XpertHR provides detailed guidance on the legal basics of employing foreign nationals (subscription required) and on issues relating to the national minimum wage.