Table 1.

Data selection

Analysis sample	Years	Sex	n complete country-year-level dataa			n complete country-year-level data + individual variablesb			% missing
			L1	L2	L3	L1	L2	L3
Model 1 (schoolwork pressure)	2002–2018	Boys	318,494	188	43	294,426	188	43	7.56
		Girls	332,010	188	43	315,881	188	43	4.86
Model 2 (family structure)	2002–2018	Boys	315,212	186	43	291,338	186	43	7.57
		Girls	328,664	186	43	312,667	186	43	4.87
Model 3 (time spent on internet)	2010–2018	Boys	142,232	81	31	131,287	81	31	7.70
		Girls	146,784	81	31	139,081	81	31	5.25
Model 4 (obesity)	2002–2018	Boys	318,494	188	43	294,426	188	43	7.56
		Girls	332,010	188	43	315,881	188	43	4.86
Model 5 (final)	2010–2018	Boys	137,178	78	30	126,538	78	30	7.76
		Girls	141,538	78	30	134,027	78	30	5.31

L1 = level 1, i.e., individuals; L2 = level 2, i.e., country-years or years within countries; L3 = level 3, i.e., countries

^acases from countries where data on the proportion of adolescents with high psychological complaints, the respective predictor(s), and the control variables income inequality and economic performance at the country-year level were all available within the same year for at least two years

^bcases from countries where data on the proportion of adolescents with high psychological complaints, the respective predictor(s), and the control variables income inequality and economic performance at the country-year level were all available within the same year for at least two years AND where data on the individual level variables on high psychological complaints, family affluence, and age were complete