Table 5

The quadratic conditional Engel curve by income levels

	Food	Health	Education	Housing	Clothing	Entertainment	Durable goods	Alcohol	Energy and Electricity
Low income
Dummy variable for tobacco spending (d)	0.8668	−0.9381	−0.7905	−0.9548	−0.2964	−0.0218	1.8458	0.0759	0.1227
Dummy variable for tobacco spending (d)	−2.6588	−1.1437	−1.6237	−1.4281	−0.1875	−0.2572	−2.5804	−0.2955	−1.1686
Total amount of tobacco spending (q)	0.0252	0.0574	−0.0928**	−0.0406	0.0024	0.0087	0.0298	0.0164**	0.0689**
Total amount of tobacco spending (q)	−0.0554	−0.0383	−0.0388	−0.0311	−0.0096	−0.0122	−0.0329	−0.0078	−0.0327
Sample size	2.656	2.656	2.656	2.656	2.656	2.656	2.656	2.656	2.656
Middle income
Dummy variable for tobacco spending (d)	6.366	−0.3487	−7.683	0.1043	−0.7711	0.3725	4.2255	1.2663	2.4327
Dummy variable for tobacco spending (d)	−7.3075	−2.2694	−11.2654	−3.0513	−1.2889	−0.9297	−9.1312	−1.3739	−3.0387
Total amount of tobacco spending (q)	0.111	−0.0113	−0.2212	−0.009	−0.0226	0.013	0.1785	0.027	0.0533
Total amount of tobacco spending (q)	−0.1386	−0.0476	−0.2286	−0.0375	−0.0261	−0.0202	−0.1907	−0.0278	−0.0615
Sample size	3681	3681	3681	3681	3681	3681	3681	3681	3681
High income
Dummy variable for tobacco spending (d)	−1.8405	0.106	−0.1495	−1.3928	−0.1285	0.0643	4.4280*	−0.0137	−0.2655
Dummy variable for tobacco spending (d)	−2.1203	−2.2976	−1.1693	−1.5137	−0.22264	−0.6638	−2.6259	−0.2489	−0.5523
Total amount of tobacco spending (q)	0.0337	−0.044	−0.0065	−0.0094	0.0024	0.0107	−0.0195	0.0049	0.0079
Total amount of tobacco spending (q)	−0.0314	−0.0234	−0.0187	−0.0169	−0.0049	−0.0106	−0.0248	−0.0031	−0.0113
Sample size	2794	2794	2794	2794	2794	2794	2794	2794	2794

*, ** and *** show significance levels at 10%, 5% and 1%, respectively.