Immigration and Social Security in Spain

We try to build a quantitative-theoretical framework to understand the impact of immigration on the Spanish pension system, both during the last ten years and, more importantly, during the future fifty years. In other words, we look at the recent past in a tentative to predict the future. Because we are perfectly aware of the intrinsic impossibility of predicting future economic events at an horizon longer than a few days, we interpret our simulations and predictions with a very large of clinical judgement. It is not that we do not trust them: as far as we can tell, given the information available today, these are the best predictions we can think of. On the other hand, being quite aware of the dramatic limitations in the information available to us, we spend most of our time pointing out the multiple reasons why our predictions may turn out to be completely wrong. In this sense, all we are attempting here is to offer a frame of reference for an educated policy discussion, and for further, more powerful and deeper, economic research.