COMPLEXITY OF DOMESTIC PRICES OF HORTICULTURAL PRODUCTS AND MONTHLY ECONOMIC IN-DEXES

Abstract

One-dimensional profiles of agricultural product prices, domestic price indexes for consumers and producers, and exchange rates of Mexican pesos per US dollar can be characterized by the statistical fractal dimension D, estimated through the slopes of the log-log geostatistical variograms, assuming that the relationships between the average variances and time increments are described by a power law. This assumption corresponds to the concept of self-affinity. D values between 1 and 1.5 indicate predictability, while D values from >1.5 to 2 indicate chaotic behavior and unpredictability. Monthly price series of white garlic, ‘bola’ onion, medium-size cabbage, yellow peach and ‘Flor de Mayo’ beans show finite variance, while the other variables showed infinite a priori variance. The white garlic price series is described by D=1.460.179, with a behavior similar to the Brownian motion fractal function.