A key labor-market ratio has tumbled near record lows — and Deutsche Bank's top economist says the US has to create a whopping 30 million jobs to reach a new all-time high

· In April, the employment-to-population ratio — the percentage of those above 16 who currently have a job — fell to an all-time low of 51.3%. That means only half of working-age Americans are currently employed. 
· "To get the employment-to-population ratio back to where it was at its peak in 2000 we need to create 30...