About the Authors

Juan A. Crespo

juan.crespo@uam.es

Affiliation Departamento de Economía Cuantitativa, Universidad Autónoma de Madrid, Madrid, Spain

Yungrong Li

Affiliation Departamento de Economía, Universidad Carlos III de Madrid, Madrid, Spain

Javier Ruiz–Castillo

Affiliation Departamento de Economía, Universidad Carlos III de Madrid, Madrid, Spain

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JAC JR-C. Performed the experiments: JAC YL JRC. Analyzed the data: JAC YL JRC. Contributed reagents/materials/analysis tools: JAC YL JRC. Wrote the paper: JRC JAC.