I came across this phrase while reading an article by Paul Krugman on the New York Times website. Here's the quotation (emphasis added):
… non-GIPSI [the group of Eurozone nations – Greece, Italy, Portugal, Spain, Ireland – that are grappling with the debt crisis, my note] European leaders should realize that what the GIPSIs really need is a general European reflation. So let's hope that they get this, and also give each of us a pony.
Now, I understand that this is a sort of witty remark, but I cannot figure out what he's referring to. I know that there's a horse breed named “Gypsy”, but I suspect there may be another reference—an idiomatic one, perhaps—I don't know of.