The euro crisis may have eased recently, but companies and countries in the common currency zone still aren’t investing enough to fuel growth. The best solution, a Berlin economics institute argues, is to establish an EU-wide investment fund. […] But simply ratcheting up public expenditures, as some Southern European governments have advocated, is not a sound strategy for improving the situation, the [German Institute for Economic Research (DIW)] believes. “One of Europe’s biggest weaknesses is the lack of private investments,” (Marcel) Fratzscher says. “We have to close the gap by way of a European investment agenda.” …