How bad is China's economic slump? It's impossible to tell

Hong Kong (CNN Business)- Companies and executives around the world are desperately trying to gauge the severity of China's economic slowdown. But getting a clear picture is very difficult.

Growth in the world's second-biggest economy cooled last year to its lowest level in almost three decades, according to government data. Top global brands including Apple (AAPL) and Caterpillar (CAT) have blamed weakness in China for their disappointing earnings.