well...I am basing it on the fact that Johns Hopkins Phd program in Economics is not even top 20 in the country...
the top econ phd programs are (not in order) Harvard, Yale, Stanford, Columbia, Berkeley, Stanford, UPenn, Northwestern, Chicago, Princeton, Michigan, UCSD, etc, all strong in Mirco, Macro, Development, International Economics, I.O., Public Finance and Johns Hopkins is not strong in any particular field...
so given the fact that Johns Hopkins Phd program in Economics is NOT top-notch, I doubt that the SAIS (master program) has top-notch economics preparations...
Of course SAIS is clearly top-notch in IR and placing people in DC organizations but in terms of economics, it may not be the case...so I wouldn't think SAIS' selling point is its economics...