"Poverty has no causes. Only prosperity has causes."
– Jane Jacobs
That cause is Freedom, which makes possible economic growth. Socialism or any oppression limits prosperity.
Freedom has causes
Freedom requires self-government – "government of the people, by the people, for the people", the Rule of Law, a Constitution designed to protect Individual Rights and to limit Government.
All else – democracy, socialism, dictatorship by any name, anarchy, riots – brings destruction and misery.
"To live under the American Constitution is the greatest political privilege that was ever accorded to the human race." – President Calvin Coolidge