In India and probably some other countries, it is mandatory for finance or money bills to be introduced in the Lower House. What is the reason behind this? Although the Upper House also votes upon the bill if it gets passed in the Lower House, I want to know why the Lower House gets priority over the Upper House.
The Lok Sabha in India is elected on the basis of general direct elections. The members are chosen from single-member constituencies through first-past-the-post system for a term of five years.
OTOH, only one third of the Rajya Sabha members are replaced every second year, that too through indirect elections by an electoral college.
Thus, the Lok Sabha tends to be the "Popular House".
Moreover, India has a Parliamentary system wherein the Executive is responsible to the Lok Sabha. Thus, the Lok Sabha has the responsibility to control the Executive, and financial control is one major means to achieve that.
The Lok Sabha, and not the Rajya Sabha, has the power to dissolve the Executive. The defeat of a Money Bill in Lok Sabha effects to the resignation of the Government. Though the Bill is passed to the Rajya Sabha, it has no powers even to amend or reject the same.
The basic difference is that the Lok Sabha is the "Council of the People" which maintains the popular character, while Rajya Sabha is the "Council of the States", which maintains the federal character of the Government.