s support allowed me to finish high school, enroll in college, and pursue my master's. Inmaculada (my advisor) not only opened the door for me to accomplish my dream of reaching the doctorate level, her patience, guides, and wise comments were key and drove me to deliver this document.I am incredibly grateful to Juan Esteban Saavedra, who landed my ideas and motivated me during the process. Andrés Córdoba, who helped me with the code when I was lost.Sarah Belford encouraged me, discussed, and helped me with the English to improve this document.