Integral Formula for the Determination of Price Variations in Public Contracts of Road Works

The objective of the research is to generate a new formula to determine the variation in prices in a public works contract that allows the financial balance of the counterparts. The methodology for calculating and adjusting the price variation in public works contracts is given as a function of the K factor, which is a number that comes from the calculation of polynomial formulas whose theoretical basis lies in the price indices, which are established in a legal framework of mandatory use of the polynomial formula to determine the K factor, with eight monomials in the budget and the quantity of supplies that exceeds one hundred. It is considered a subjective margin since its elaboration depends on the discretion of the one who elaborates on the polynomial formula. The investigation questions the procedure established by the state regulations for the calculation of the polynomial formula and shows the margin of error that exists between the value obtained by the method set for regulations and that obtained using the entries of the work budget. The result shows the positive variation in inputs, and the prices have increased, with adjustments paid in the contracts with the benefit of contractors.