German officials are scrambling to find more qualified workers for the many open jobs employers say they can’t fill with the existing work force. They’ve visited Canada to learn how to attract more highly qualified immigrants and have eased immigration requirements for qualified professionals. Without immigration, there would be an additional shortage of 442,000 of the so-called STEM specialists in Germany today, according to Axel Plünnecke, the head of a division dealing with education and migration at the Cologne-based German Economic Institute. He was referring to Science, Technology, Engin…