This paper reviews some of the recent research findings on consumers' attitude and willingness to pay for genetically modified food (GM food) in China and hormone induced milk in the US. The economic impact studies on mandatory labeling for GM food around the world are also discussed. The general consensus from the impact studies in the literature is that it raises the price of the food products depending on the cost of labeling, labeling characteristics, and the structure of the market. Using survey data from the US consumers this study finds that mandatory labeling for hormone (bST) induced milk would increase the economic benefit to the society raising the consumer and producer surpluses and provides the right to choose in the hands of the consumers.