Caterpillar (NYSE: CAT) the global supplier of construction and mining machinery came reported sluggish growth. Their second quarterearnings came in at $1.45 per share, missing analysts' estimates for $1.68 per share. Now what does this tell us about the global economy?Well seeing as how Caterpillar sells construction supplies all around the world if they aren't making bank it usually means the global economy isn't growing much.