The region's financial turmoil has subsided since the European Central Bank in September 2012 offered to buy the government bonds of indebted countries such as Spain and Italy. That lowered their borrowing costs and defused fears of a disastrous government default.
Schmieding said Germany was tied to the eurozone's fate since it makes big-ticket items such as industrial machinery and autos that it exports to fellow European countries.
"Whether or not companies and households at home or abroad buy these big-ticket items reflects their level of confidence in the future," he wrote in a research note. "That helps to explain why the German business cycle is driven so much by the escalation or the easing of tensions in the eurozone, despite Germany's underlying fundamental strength."
Official data for the second quarter are due on Aug. 14.