of the copper industry. In the agreement, it was established that the Chilean government could buy within the next 13 years (counting from 1970) the remaining 49% of the foreign ownership from the multinational corporations, but only after having paid at least 60% of the current debt due from the purchase of the original 51%. It also fixed a clear formula for the valuation of the assets to be bought, for the liquidation of profits, for the increase of direct investment in new works, and related issues. Third stage of nationalization The process of "negotiated nationalization" met with vociferous criticism from the leftist political parties, and from a section of the President's own Christian Democratic Party. The idea was accused of bowing to American imperialism, being too slow and too expensive. In the 1970 presidential election, the outright nationalization without compensation (known as the Chileanization of copper) became one of the main campaign issues. Two out of the three presidential candidates incorporated the idea into their political platforms, while the third opted for a faster version of the "negotiated nationalization". After socialist candidate Salvador Allende won the election, he promised to deal with the issue head-on. In fact, at the beginning of 1971, he sent Congress a project for a constitutional amendment that would allow him to nationalize outright all mines, and to transfer all present and future copper fields to the state. Congress passed this amendment on July 11, 1971, by a unanimous vote, and based on it, on July 16, 1971 law 17.450 was promulgated, and became effective immediately. The event was celebrated as the Day of National Dignity (). In principle, there was complete agreement about the process of nationalization of the mines among all political parties represented in the Chilean Congress, as indicated by the unanimous vote that approved law 17.450. When it came down to the particulars, however, there was much concern about the political use that the Allende administration would make of it. Even so, the bigger concern was for the expected reaction of the U.S. government. Compensation Originally, the expropriation was based on the book value of the properties. Nevertheless, the Allende administration introduced the idea of "excessive profits" into the calculation of indemnization for the mines. This idea was based on the concept that the multinational corporations had reaped profits far in excess of what was considered "normal business practice". The way