Deflactor: índice de precios de Laspeyres
\[\frac{{{V_t}}}{{LP}} = \frac{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{it}}} }}{{\frac{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{i0}}} }}{{\sum\limits_{i = 1}^N {{p_{i0}} \cdot {q_{i0}}} }}}} = \sum\limits_{i = 1}^N {{p_{i0}} \cdot {q_{i0}}} \cdot \frac{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{it}}} }}{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{i0}}} }} \to \frac{{{V_t}}}{{LP}} = {V_0} \cdot PQ\]
Laspeyres no es un auténtico deflactor, aunque es el que suele utilizarse.
Deflactor: índice de precios de Paasche
\[\frac{{{V_t}}}{{LP}} = \frac{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{it}}} }}{{\frac{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{it}}} }}{{\sum\limits_{i = 1}^N {{p_{i0}} \cdot {q_{it}}} }}}} = \sum\limits_{i = 1}^N {{p_{i0}} \cdot {q_{it}}} \cdot \frac{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{it}}} }}{{\sum\limits_{i = 1}^N {{p_{it}} \cdot {q_{it}}} }} \to \frac{{{V_t}}}{{LP}} = \sum\limits_{i = 1}^N {{p_{i0}} \cdot {q_{it}}} \] Valor actual de un conjunto de bienes a precios del año base.