The replies to this made me think harder about pyramid schemes vs population pyramids. I concluded it is in fact OK to bring in young working people from elsew

The replies to this made me think harder about pyramid schemes vs population pyramids. I concluded it is in fact OK to bring in young working people from elsewhere to fund the retirement and social services of those already here and ageing. I was thinking there would be a problem as those immigrants in turn aged and switched from net contributors to net claimants, but I hadn't taken into account that they like all of us die off as they age: indeed, what makes the pyramid a pyramid.