I think the UK has a similar policy with pensions with a cap around £1m. Not saying it's a good or bad idea as I really havn't studied the economics of it, but

I think the UK has a similar policy with pensions with a cap around £1m. Not saying it's a good or bad idea as I really havn't studied the economics of it, but other countries definitely do it. Though a UK pension is more like a 401(k) (pre tax) than a Roth (after tax).