Egy 1947-es előadásában L. Albert Hahn a keynesiánus gazdaságpolitikát az illúzió gazdaságpolitikájának nevezi. Miért? Idézem: ’For it presupposes an economy whose members do not see through the changes brought about by monetary or fiscal manipulation — or, as some might say, the swindle. Above all, it presupposes that people are blinded by the idea that the value of money is stable — by the "money illusion," as Irving Fisher called it.’. Persze a gazdaságpolitika, vélekedik Hahn, ideig-óráig alapozhat erre az illúzióra. De csak ideig-óráig. Illúzió ugyanis azt gondolni, hogy a gazdaság szereplőit tartósan illúzióban lehet tartani. ’However, to assume that when the value of money is consciously and willfully manipulated, the members of the economy will be bluffed for any length of time and will allow dupes to be made of themselves is an illusion.’. Az emberek ugyanis racionálisak, és egy idő után elkezdenek alkalmazkodni: a kormányzati illúziókeltés része lesz a gazdasági szereplők várakozásainak. Például: ’In our inflation-conscious times, however, when everyone — certainly every union leader — seems to carry a living-standard index curve in his pocket, the money illusion can hardly fool anyone for long.’. De vehetünk másik példát is, ami kellően figyelemre méltó, így érdemes kicsit hosszabban idézni: ’A community that takes into account governmental investment but not the resulting debt would be just as short-sighted as is a community that regards an increase of war loans in the hands of individuals as an increase of wealth for the community, or a private enterprise that enters its assets but not its liabilities on its books. The businessman, especially the investor, is well aware of these matters, as is evident from his attitude toward an increasing public debt — his fear of declining profit margins because of the threat of higher taxes. In the long run the entrepreneur responds to deficit spending by compensating reactions; with the result that private investment in general declines as government investment increases. As soon as prospective taxes are calculated as present costs, private enterprise becomes unprofitable and is given up.'. Úgy tűnik, Hahn ebben az 1947-es előadásában a keynesiánus gazdaságpolitikának a racionális várakozásokon alapuló kritikáját nyújtja, ricardói-ekvivalenciástól mindenestől.