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The sign is to support the Nazi belief that Jewish business owner were purposefully destroying the economy.
This occured due to the rise of the totalitarianism government in Germany,the Nazi Party. The economy of Germany was greatly shook after the defeat of WWI, and many suddered from poverty. Hitler then turned the blame of the defeat to the Jews,claiming that they're the one who corrupted the German economy,thus taking action to “punish” and boycotting the Jews.
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