The two lessons learnt by the economists and politicians during the Second World War were: First: An industrial society based on mass production needs mass consumption. For mass consumption, steady income was necessary and for stable income, full employment was necessary. For this, the government has to take step to minimise the fluctuation of price, production and employment. Hence, economic stability could be ensured by the government intervention. Second: The goal of full employment could be achieved only if the government controls the flow of goods, capital and labour.