Source: https://www.researchgate.net/profile/Brigitte-Dormont/publication/315219064_Modeles_dynamiques_de_demande_de_travail_specification_et_estimation_sur_donnees_de_panel/links/58d942f045851578dfb135f9/Modeles-dynamiques-de-demande-de-travail-specification-et-estimation-sur-donnees-de-panel.pdf