Manufacturing activity shrank in New York in August with a monthly business index dropping into the red, the Federal Reserve Bank of New York said Wednesday. The Empire State Manufacturing Survey taken the first half of each month indicates manufacturing activity \"slipped below zero for the first time since October 2011,\" the New York Fed said. The general business conditions index gave up 13 points to reach minus 5.9. The new orders index was below zero, the break-even point between contraction and growth, for the second consecutive month, while the shipments index dropped six points to 4.1. The index indicating the number of employees was positive at 16.5, but gains in that category were slower than July, as the index \"inched lower,\" the Fed said. The index for hours worked rose slightly to 3.5, remaining positive, but staying within sight of the break even point.