The Effects of Tax Revenue by Deductions of National Income Tax and Individual Inhabitants Tax The national income tax and individual inhabitants tax have similar deduction systems, but their respective tax rates are different. The national income tax rates are progressive, whereas the individual inhabitants tax is a flat tax. This paper analyzes the effects on tax revenue by deductions from these income taxes by estimating tax revenue loss. The result of the analysis shows that (1) social security deductions cause the biggest tax revenue loss, and (2) social security deductions from the national income tax have a negative income redistributive effect. This paper suggests that some deductions for income taxation should be reconsidered. Toshiyuki Uemura JEL H24 Keywords Income taxation, Tax revenue loss, Social security deduction 1. 319
68 3 2 10% 6% 4% = 320
2012b,2014 2012b,2014 1) 2001 2010 2008 2) 1 2 3 4 2. 2012 2 12 2,000 1) 2012b 2014 2000 2012 2) 2002 2011 2011 321
68 3 2 12012 n K 1 100 3,046,640 2,506,349 0 103,005 2 100 200 5,802,634 8,561,036 64,340 406,431 3 200 300 7,063,352 17,831,748 250,827 859,089 4 300 400 7,685,617 26,937,978 448,381 1,354,745 5 400 500 6,028,296 26,959,580 504,287 1,638,644 6 500 600 4,118,329 22,549,041 505,293 1,478,312 7 600 700 2,512,744 16,253,494 445,424 1,108,247 8 700 800 1,732,178 12,921,614 477,982 863,396 9 800 900 1,112,457 9,422,638 461,166 602,432 10 900 1,000 745,296 7,052,353 419,488 428,414 11 1,000 1,500 1,210,630 14,240,211 1,208,638 730,229 12 1,500 2,000 219,963 3,767,280 539,073 127,478 41,278,136 169,003,322 5,324,899 9,700422 2 2 500 600 4,118,329 1,478,312 1,478,312 2,640,017 322
3 2012 m 0 38 1 38 2 25 63 (1) 3 10 48 (1) 4 45 83 (1) 5 6 38 (1) 7 38 8 25 63 (7) 9 20 58 (7) 10 10 48 (7) 11 37 75 (7) 12 27 13 13 40 (12) 14 27 15 8 35 (15) 16 27 17 18 19 20 M 3 4 20 2 12 2 20 =12,582,912 1,048,576 =12,582,912 12 3) 3) 323
68 3 4 2012 m 0 33 1 33 2 23 56 (1) 3 5 38 (1) 4 27 61 (1) 5 6 33 (1) 7 33 8 12 45 (7) 9 12 45 (7) 10 5 38 (7) 11 23 56 (7) 12 26 13 4 30 (12) 14 26 15 4 30 (15) 16 26 17 18 19 20 12 n(n = 1, 2,, 11, 12) 20 m(m = 1, 2,, 19, 20) n Kn n m D n m n m S n 1m S n 2m (1) (2) r = 1 r = 2 S n 1m + S n 2m = 1 S n 1m = Dn m K n (1), Sn 2m = Kn D n m K n (2) n i m = 1 r = 1 m = 2 r = 2 m = 20 r = 2 i M n i (1, 2,, 2) M n i (r n i ) 3 4 3 4 324
n M n i I n i (3) I n i i (4) n K n I n i = K n Π 20 m=1s n r (M n i (r n i )) (3), K n = Σ ii n i (4) M n i 38 5 2012 500 600 4,118,329 4,021,145 2,950,851 733,833 n i Y n i M n i i T n i (5) Φ t d 325
68 3 n 5 22012 K 1 100 3,046,640 852,433 23,464 2 100 200 5,802,634 4,342,166 716,433 3 200 300 7,063,352 6,596,522 2,193,954 4 300 400 7,685,617 7,439,674 3,446,530 5 400 500 6,028,296 5,871,718 3,505,782 6 500 600 4,118,329 4,021,145 2,950,851 7 600 700 2,512,744 2,460,914 2,128,607 8 700 800 1,732,178 1,698,540 1,663,754 9 800 900 1,112,457 1,092,889 1,178,410 10 900 1,000 745,296 724,709 840,109 11 1,000 1,500 1,210,630 1,176,045 1,486,619 12 1,500 2,000 219,963 209,866 294,344 41,278,136 36,486,621 20,428,857 T n i = Φ(Y n i, M n i (r n i ), t, d) (5) t 6 2007 6 2007 195 195 330 330 695 695 900 900 1,800 1,800 5 10 20 23 33 40 4 6 326
I n i i T n i (6) n R n (7) T R R n = Σ ii n i T n i (6), T R = Σ nr n (7) 1 Y n i 2 3 4 T n i n i T n i n i Y n i 2 Y n i i T n i R n R n 1 Y n i R n 1 327
68 3 Y n i Y n i 3. 4) R0 n R n (8) R n R0 n L n R0 n > R n L n > 0 L n (9) T L L n = R0 n R n (8), T L = Σ n L n (9) 3 3 2006 4) 2008 2011 328
2007 2012 1 T R T L T L T R 2010 2011 16 16 0.50 1 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 2007 2008 2009 2010 2011 2012 T L T R 329
68 3 1 2 2 2012 1 L n K n 1 1 1 450,000 2 1 400,000 350,000 300,000 250,000 200,000 2012 2012 2012 2012 2012 2012 150,000 100,000 50,000 0 L n K n 330
4. 1 331
68 3 1999 50 2008 38 2010 37 2012a APIR Discussion Paper Series No.24 2012b 66 2 2014 175 2011 43 2002Vol.18, No.2 2008RIETI 08-J-033 1995 2011 25 1 2010 2001 57 332