“…Thirdly, among the socioeconomic factors , most studies in this field consider the gross domestic product (GDP), per capita income [ 12 , 22 , 24 , 25 , 26 ] or some indicators of income distribution [ 27 , 28 , 29 ]. Education [ 13 , 30 , 31 ], unemployment [ 32 , 33 ], inflation [ 34 ], gross capital formation [ 35 ], pollution [ 12 , 35 , 36 ], environmental quality indicator [ 37 ] and financial development [ 38 ] are other socioeconomic factors included in this type of empirical research. Additionally, it is usual to consider other specific variables restricted to government expenditures.…”