In my opinion this will be a good thing as so much of the economic "growth" we see in the world today is a vacuous re-packaging of frivolous fancies to meet imaginary needs fueled by an incentive to spend currency that is always losing value. Things that satisfy a genuine pressing need will continue to be invented, bought and sold and this is all that is necessary for a vibrant healthy economy.
The idea of Bitcoin shrinking the economy is something I can really place and I think such can't happen and why will it shrink the economy when it's set aside to meet up individuals needs in the long run and mind you it's decentralized nature makes it available in such a way that it amounts to the growth and stability of one or organization.
You can decide to invest in Bitcoin or not but definitely it doesn't change the fact that it could be replaced with anything, yes the price changes overtime, do if you think Bitcoin is dropping the economy of a country why not give it a try like to invest in it for awhile and see the outcome yourself and I bet you you'll be grateful you did.