 They are not really middle class, but only theoretically lower middle class who have economic ability of middle class.For example, a man who earns $40,000 a month pays "negligible" amount of income tax, while a family composed of a woman earning $30,000 and a man earning $30,000, totally earning $60,000 a month need to pay "very heavy" tax.The GST was supposed to curb this social problem.