Step 1: Recall the origin of the original Nobel prizes.
Alfred Nobel's 1895 will set up prizes in physics, chemistry, medicine, literature, and peace, but economics was never part of his original list.
Step 2: Trace how the economics prize got added.
In 1968, Sweden's central bank, Sveriges Riksbank, created a new award to mark its 300th anniversary and tied it to the Nobel name, calling it the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel. It is awarded alongside the other Nobel prizes but is technically a separate award funded by the central bank, not a university or the IMF.
Final Answer:
The Nobel Prize in Economics was instituted by Sveriges Riksbank. \[ \boxed{\text{Sveriges Riksbank}} \]