Static constructor not working for structs

The static constructor isn't executed because you are not using any static members of the struct.

If you use the static member currInterestRate, then the static constructor is called first:

Console.WriteLine(SavingsAccount.currInterestRate);

Output:

static ctor of SavingsAccount
0,06

When you are using a class, the static constructor will be called before the instance is created. Calling a constructor for a structure doesn't create an instance, so it doesn't trigger the static constructor.