"Savings help the economy."
Translation:Η αποταμίευση βοηθά την οικονομία.
What about "saving" in the singular which has an abstract sense, the present participle of the verb to save, whereas the synonym for savings is a " fund of money". I suppose the only important thing is that " οικονομίες" is savings, whereas " αποταμίευση" is thrift or being careful with your money. I hope that's right :-)