When we have the following utility function :
U_{t}=U_{t}(C_{t} , L_{t} , M_{t})
The first derivative to Money is higher than zero.
But what about the second derivative ??
In some utility functions in DSGE I think second derivate of money is higher than zero. I this situation what we can say about the concavity of the utility function?
Can we say this utility function is not strictly quasi concave or not ?
According to this point that second derivatives should be less than zero because utility function is strictly quasi concave.