Answer
Wa `alaykum as-salamu wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- Riba (usury) is a form of injustice that goes against the spirit of social justice.
2- Social justice can be achieved by many ways, and interest is never one of them.
In his response to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
These issues need a lot of discussion and cannot be fairly covered in a few words. Let us consider the following points:
1- Riba is injustice, because it takes a part of the property of another person while what the lender owns does not increase.
2- Ribais not the tool of creating social justice between the poor and the rich. We see many societies that have relatively high levels of social justice (no absolute poverty), and yet it is based on Riba. Some of them (e.g., Singapore and Hong Kong) are centers of Riba.
Riba does affect the economic justice, as it allows a person to take unjustly the fruit of efforts of another.
3- Tools of social justice are essentially to offer work opportunities at fair wages. This requires development plans based on and aimed at improving productivity of the masses and creating an educational system that is technology-oriented.
We see in Egypt that those who are equipped with this kind of education are getting better income and better opportunities.
Imagine if everyone is educated this way and is supported with finance in an appropriate way: mass finance based on real contribution to asset building (this is what Islamic finance does: provision of machines, goods, venture capital on sale, lease, and sharing bases).
4- Paper money is an invention of humans that must not be underestimated. It is in fact great, and it helped the economy, And so are central banks. They do not have to be based on interest. They can be based on sharing, sale, and lease. There is nothing glorious about gold and silver as money. Why having it when you can have money without cost?
Misuse of money by a corrupt government is always possible, even if we use gold. It happened in the past in Egypt itself, as we are told by Al-Maqrizi. We need a good and transparent government, not gold money.
5- Phasing out interest from the financial market should be gradual and must be our target, but do not rush to it too fast.
6- We need to enforce Zakah and Awqafin our social system.
Almighty Allah knows best.