History tells us of the constant movement of peoples and what happens when they do. It is a complicated story and means that when discussing movements in our own time you are dealing with the past as well as the present and all the ideas, beliefs and views involved and their inherent conflicts.
Your migration can be my invasion. My expulsion of unwanted people will be your refugees. Our claim to land and authority is also our way of saying who will own and benefit from it. But often we will not agree and the disputes will trigger movements of people. Down the centuries it has often been a bloody business.
In the 1940's we knew numbers of refugees of different kinds. These included the post war displaced persons, there being a number of places for them in the vicinity. In the 1950's, we have forgotten the upheavals in the East of Europe in 1953 that triggered added movement of people to The West, especially from East Germany and again, Poland and this continued.
In 1955 the winter going into 1956 was very bitter in Germany . The rivers froze, I recall playing football on The Weser. It was possible to walk across The Elbe into West Germany. Many did and sometimes even the patrols of the East who were supposed to prevent it. In 1956 there were further events and numbers of Hungarians and others arrived notably in London, to add to the displaced persons already with us. Not long after the war there had been laws and regulations etc. aimed at closing the camps. Some did, but some were still mini-towns into the 1960's.
As well as the larger camps, some local authorities had patches that were used. There were plenty of WW2 Nissen huts available. But many then were housed in the cheaper rental areas and to the fury of many had priority for the envied council houses. Those from the East of Europe were followed by many from places in the former Empire where political freedom had not necessarily meant peace and tolerance of minorities.
There were divided views about this, not least between some people in the urban areas who were adversely affected and which took most of them and those in other places who could be generous to their small numbers and for whom the principles of free and open movement had little local impact.
Fifty years on we are in a different world. Only now, instead of thousands the figures are in the hundreds of thousands with the potential to be millions. Moreover, the arrivals do not come to a land in which they will have to adjust to local laws and lifestyles because there are few other options.
Instead of three channels of British TV then, now they can watch their own versions from their homeland. The internet can bring their place of origin into their own living space. There is little they need to change in terms of eating or the other routines of life. In short they might be living in one place for convenience, income and housing etc. but their culture, lifestyle, etc. are those of another country.
If the new is more advantageous or generous than they could hope for in their homeland, it is not surprising many will want to come. Our problem is that some will have strict beliefs that are not just alien, or beyond our law but are in conflict with it. Another, inevitably, is if the proportion of loose young men and the crimes and gangs that are often the core of their activities.
England is one of the most intensively populated pieces of land on the planet, the result of many migrations so just about all of us have migrant forebears to a greater or lesser degree. Back a few generations and all those forebears of mine moved around the Atlantic Isles, some by choice, some after having become unwelcome, some by famine and some by clearances.
The open borders and free movement ideals born out of mid 20th Century and later ideals and beliefs has been encouraged by the idea that the State has an unlimited capacity to provide either by taxation or by creating new money at will. It is obvious that if the population increases by millions then the circulation of state money provided plus extra spending required will have the effect of rising GDP.
The figures can be presented to suggest that this will be good. But they do not take account of the opportunity costs and the many and substantial other real costs that come in train. In particular they do not allow for very many new migrants not seeing themselves as UK citizens but local communities of other jurisdictions. Which may mean that the tax does not get paid, tax avoidance becomes common and their money goes somewhere else.
So given the costs of increasing world population there are other issues. What might happen with rising food costs? Or if the money tree stops growing or even sickens, or if some local communities or even nations become ruled by gangs of violent men and not either local or central government?
Currently, there are parts of the world with over a billion population. If events, disruptions or crises trigger greater movement; say 5% of the population affected how many millions of migrants or refugees is that on the move?
And if up to 10%? And what were the percentage figures for the Irish Famine and Highland Clearances?