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Competition is a relevant element in any open economy. Public policies are necessary to induce economic efficiency and to create conditions to preserve or stimulate a competitive environment. This paper aims to assess the competitiveness of hydrous ethanol price in a period of political, social and economic crises, in 15 Brazilian state capitals between the years 2012 and 2019. We compared the ethanol–gasoline price ratio behavior in two different periods, before and after the import parity price policy implemented by Petrobras in 2016. Mann–Whitney and Levene’s tests, two non-parametric statistical methods, were applied to verify significant changes between these periods. The implementation of changes in Petrobras’ pricing policy from 2016 onwards caused a statistically significant increase in the ratio coefficient of variation in two-thirds of the distribution market and more than the half of analyzed retail markets. Second, overall, the cities that showed statistically significant changes in the median and coefficient of variation in the distribution market price ratio were followed by the retail market. Our findings suggest that government interventions in the fuel and byproduct final selling prices to distributors negatively impact competition between companies that are part of the fuel distribution and retail chain, also affecting the sale of biofuels in Brazil and discouraging the initiatives to use renewable fuels to reduce the emission of pollutants.

The global energy landscape is rapidly changing, including the transition to a low carbon economy and the use of liquid biofuel. The production of liquid biofuel has emerged as an alternative to the use of fossil fuels for purposes of energy conservation, carbon emission mitigation and agricultural development. In this article we study the co-movements between hydrous ethanol and gasoline C in the Brazilian retail market. A multi-scale cross correlation analysis was applied to the Average Retail Margin time series of hydrous ethanol for fifteen relevant retail markets in Brazil to analyze the competitiveness of hydrous ethanol towards gasoline C. The empirical results showed a remarkable different behavior between hydrous ethanol and gasoline C, for any time scale, regardless of geographical distance or regional differences.

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Dengue is a complex public health problem that is common in tropical and subtropical regions. This disease has risen substantially in the last three decades, and the physical symptoms depict the self-affine behavior of the occurrences of reported dengue cases in Bahia, Brazil. This study uses detrended fluctuation analysis (DFA) to verify the scale behavior in a time series of dengue cases and to evaluate the long-range correlations that are characterized by the power law [Formula: see text] exponent for different cities in Bahia, Brazil. The scaling exponent ([Formula: see text]) presents different long-range correlations, i.e. uncorrelated, anti-persistent, persistent and diffusive behaviors. The long-range correlations highlight the complex behavior of the time series of this disease. The findings show that there are two distinct types of scale behavior. In the first behavior, the time series presents a persistent [Formula: see text] exponent for a one-month period. For large periods, the time series signal approaches subdiffusive behavior. The hypothesis of the long-range correlations in the time series of the occurrences of reported dengue cases was validated. The observed self-affinity is useful as a forecasting tool for future periods through extrapolation of the [Formula: see text] exponent behavior. This complex system has a higher predictability in a relatively short time (approximately one month), and it suggests a new tool in epidemiological control strategies. However, predictions for large periods using DFA are hidden by the subdiffusive behavior.

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