. . "Comparative statics for a consumer with possibly multiple optimum consumption bundles" . "Comparative Statics for a Consumer with Possibly Multiple Optimum Consumption Bundles" . . . . . . . . . . . . . "Konsumtheorie" . . "Produktsubstitution" . . "Theorie" . . . . "Substitutionseffekt" . . "Offenbarte Präferenzen" . .