David Rosenberg.Rosenberg Research & Associates David Rosenberg has warned the US economy is headed for a "crash landing" or major downturn. The veteran economist cited the Philly Fed's manufacturing survey, a proven recession indicator. Rosenberg told Insider in February that the S&P 500 could plunge 25% from its current level. Don't hold out hope for a mild downturn, as the US economy looks set to suffer a severe recession, David Rosenberg has warned."Take a good hard look at this chart and tell me we are heading into a 'soft' or 'no' landing," he tweeted on Thursday.