The adoption of the mini devaluations in 1968 it had two reasons. First, the politics aimed at to prevent the speculative attacks against the domestic currency. A time that Brazil, in middle of the decade of 70, tried to keep a system of fixed exchange tax, but had a bigger domestic inflation that the international inflation, speculative flows of capital that they were a chronic problem all time that the market anticipated a depreciation. In according to place, the politics objectified to stabilize the real remuneration of the exporting sector, thus helping to increase the exportations. Beyond searching steady conditions for the payment of the importations and exportations. Two elements had characterized the politics: the small intervals between the depreciations and its small value in each episode.
Of 1968 the 1983 these intervals had been of three the ten days. Of 1984 the February of 1986, when the politics was suspended for the Crossed Plan, the frequency of the depreciations increased, passing to depreciations daily pay-announced daily in 1985 end. In the 1986 end, the mini devaluations again had been introduced. The basic rule up to 1983 (leaving of side some changes of emphasis during the period) was to devaluate the currency following the difference enters the domestic inflation measure for the General Index of prices (IGP) and the international inflation. Except for three episodes this rule it was remained up to 1983. Of 1983 middle the 1985, the rule became simpler: the cruise was tied with the dollar and the depreciations had been equal the domestic inflation (IGP). As and the third trimesters of 1985 the depreciations had exceeded the tax of domestic inflation to compensate the appreciation of the dollar (ZINI JR, 1993). From 1985, it was tried, without success, the implementation of diverse economic plans in Brazil (Crossed, Bresser, Beans with Rice, Vero and Collor), in what it refers to the exchange politics, varied enters regimes of fixed exchange, sequence in mini devaluations, depreciations of the real tax of exchange and finally floating exchange ally to the commercial opening.