In the US one of the major problems with stopping people crossing the border from Mexico to the US is the fact that many of the stoop agriculture labour in California are seasonal workers from Mexico filling jobs no American is willing to do - spending long days under the hot sun hand picking lettuce and other produce for low wages (well below minimum wage which doesn't apply to agricultural workers. The UK is facing a similar worker shortage today because Brexit is making EU workers reluctant to come to the UK to fill many jobs.
Worker shortage
In the US the problem of a labour shortage comes at both ends of the skill and education spectrum with agriculture workers at one end and 3 million high-tech worker jobs unfilled because of a lack of US citizens trained for the jobs - both are affected by President Trump's attempt to block immigrants and even temporary worker visas.
In the UK the labour shortage listed on the Visa Bureau website are mostly technical and professional positions but also includes such jobs as sous chef. But it is well known that there are many unfilled jobs which would fit the description of manual labor.
The Guardian reports that there are existing and increasing shortages in the food supply chain, healthcare, manufacturing, and hospitality industries. Those jobs sound a lot like the sort of low-wage, low-skill jobs which UK citizens may not want but the biggest problems facing employers looking to expand their workforce is that the unemployment rate in the UK is at an 11-year low, below 5% which is approximately what many economists consider full employment.
With turnover, students returning to classes, women leaving the workforce to manage family concerns, sick, retirees and disabled, it is thought that about 5% of any national workforce in a developed country will always be listed as unemployed although they are not actually ready to take a job.
That gap between open jobs and UK citizens looking for work has, until recently, been filled mostly by EU workers who could move freely from nation to nation to meet changing job markets - Brexit is changing that.
According to a recent report by the Chartered Institute of Personnel and Development (CIPD), fewer EU workers are entering the UK and an estimated one-quarter of those who are already here planning to leave, the labour shortage is reaching a serious stage in the United Kingdom where it will begin to alter company expansion plans and even current productivity.
The Winter 2016–17 edition of “HR Outlook: Views of the profession,“ surveyed 629 human resources professionals and found economic change i.e. globalisation and Brexit, is the most important factor in forcing a change in organisations.
Economic change including Brexit - 17% of the HR professionals saw Brexit as a positive while 55% saw this as a negative factor affecting UK employment.
Technology, on the other hand, is seen almost universally as a positive with the ability to telecommute or work remotely rated 95% positive and none of the HR professionals viewing this as a negative factor.
Demographics, the increasing age of workers and the increase in a four-generation workforce, is seen as about equally a positive and negative, respectively 40% positive and 38% negative.
Automation, globalisation (outsourcing), increasing social responsibility, and self-employment are all seen by almost all of those surveyed as universally positive.
(NOTE: your reporter is telecommuting from the US.)