The 52^nd issue of Semestre Económico is composed of seven articles, six derived from research and one of them from a reflection. These articles tackle different economy matters defined in the journal’s research fields such as environmental economy and sustainability, regional development and competitiveness, business economy, economic development and the study of macroeconomics and public sector aggregates. The authors in this number are sixteen in total: thirteen of the Colombian, two off them Mexican and one of them Argentinian.

The first article is titled "Optimization of soil use according to the environmental and social restrictions: the case of the Riogrande II basin", written by Juan David Osorio Múnera, Lina Marcela García-Tavera and Eduardo Andrés Bustamante Ochoa, from Universidad de Antioquia (Colombia); and Natalia Uribe Rivera, from the IHE Delft Institute for Water Education, whom from a SWAT model undergo a reformulation of the Ecosaut model for determining the optimal use of the soil according to the environmental and social restrictions. The results point towards the fact that in order to guarantee the sustainability of the basin a rotating crop system with potatoes and grass is necessary, alongside a reduction of 42 % of the soil currently used for agriculture activities.

In the second article, Orlando Mauricio Lorduy Herrera, consultant, and researcher, alongside with Jaime Eliécer Rangel Bolaños from the Universidad Pontificia Bolivariana (Colombia), present the second article titled "Analysis of the innovation indicators of a sample of manufacturer companies of Montería (Colombia)". Its purpose is to characterize the innovative processes generated by manufacturer companies in the city of Montería (Córdoba department, Colombia), taking as a theoretical reference to the neo-evolutionary theory. The results of this work make it evident that the manufacturing companies of the city of Montería are innovative and a wide sense of the word. This due to the fact that they use defensive strategies and technological activities that represent innovations oriented, especially, towards the company and the local market,

The third article is titled "To govern, (is) to capture and colonize: third cycle of neo-liberalization in the Argentinian agrarian policy" and is written by Ariel García, an adjunct researcher at the Centre for Urban Studies (CEUR-Conicet) (Buenos Aires, Argentina). In this article, from a methodological triangulation point of view, the characteristics of the third neo-liberalization cycle (2015-2019) are analyzed in the Argentinian agricultural policy in relation to its exclusive de-structuring and restructuring. The results allow the identification of capture and colonization processes by interested organizations submitted to agricultural economic elites.

The Fourth article is titled "Analysis of the opinion on homes solid residues management in Bogotá." Its authors are María del Pilar Sánchez-Muñoz, from the Universidad del Rosario (Colombia), José Gabriel Cruz Cerón, from the Universidad de Caldas (Colombia) y José Jardani Giraldo Uribe, from the Universidad Surcolombiana (Colombia). The authors applied 384 polls at homes located in the zone where the company Aguas de Bogotá S. A. ESP operated until the beginnings of 2018 in order to know the opinion that these locals had about the management of the solid residues in the city of Bogotá. The results prove the existence of a tendency towards the lack of environmental governance. The principal recommendation derived from this work is that a massive sensitization process on the importance of separating residues in the source and proper use for container and plastic bags is needed.

The fifth article is titled "Sovereign risk and direct foreign investment in Colombia, 2003-2018," developed by Cristina Isabel Ramos Barrientos, from the Universidad Nacional (Colombia), examines the effect of the sovereign risk among the flow of direct foreign investment in Colombia during the 2003-2018 period. For that, a regression analysis with MCO and MMG was used with quarterly data about the EMBIG as a proxy for the sovereign risk, IED and a group of control variables. The results show that the sovereign risk has a strong impact on the entrance of foreign investment and explains around 22 % of the total variation in the IED. It is concluded that the trust of the private agents and the grade of international trade are also determinant in the attraction of foreign capital flows.

In the sixth article, Arturo Morales Castro and Eliseo Ramírez Reyes, both from the Universidad Autónoma de México (México) and Gustavo Rodríguez Albor, from the Universidad Autónoma del Caribe (Colombia), present an article titled as "Sales forecast of companies in the food sector: a neural networks appliance," in which trough a linear model (linear regression) and non-linear models (artificial neural networks, decision tables, decision trees, and Gaussian processes) aims towards forecasting the sales for Bachoco Industries, Bafar Group, Bimbo Group, Gruma, Herdez Group, Lala Group and Maseca Industrial Group from 2006 to 2015. The results display that the multiple linear regression models show better performance at forecasting the sales for Bachoco, Bafar, Herdez, Lala and Maseca with more than 90% of data recovery for the given period.

Last but not least, the seventh article is titled as Carbon taxation in Colombia: a tax mechanism against climate change, written by the researchers Carlos Esteban Aristizábal Alzate and José Luis González Manosalva from the Instituto Tecnológico Metropolitano (ITM) (Medellín, Colombia). In their article, they reflect upon the manner in which the application of a carbon tax and its advancements in the Colombian legal ordinance contributes to the improvement of the image and increases the enterprises’ competitiveness of the country. Nonetheless, by being a tax transferable to the final cost of fuel, it will affect the market and final consumer.