Cross country scatter plots

The idea of a cross country scatter plot is to look at many examples of a process so as to cancel out idiosyncrasies and observe a general effect of some policy. A good idea generally, as a starting point.

Take this plot comparing budget balances with growth.  Take out Greece and we see that, in general, these nations do not change their budget balances very much, most of the data is centered about zero. How would this cross country scatter plot help Singapore, for example? The problem is that Singapore policy makers know more about the determinants of growth in Singapore than this scatter plot shows. That is, the scatter plot helps the economist, a step toward a theory, but for any individual nation in the scatter,  the knowledge they have about their  own nation far exceeds any information given by this plot. This plot might help Singapore export more goods to a collection of random countries but it tells Singapore nothing new about how much counter cyclical deficit it should run.