** These are the author's own case parameters, not a constructed hypothetical. ** The submission discloses this; the figures are real either way. Parameters, all weekly except where noted: Parent B (payor) $201,000/yr gross, health premium $43 Parent A (recipient) $570/wk gross, health premium $33 Three children, two under 13 and one aged 13 to 17 Box 1 -- shared financial responsibility and parenting time == TAX POSITION (net_position.py; federal AND MA constants verified 2026-09-02) == payor effective rate +30.4% recipient effective rate -38.9% (negative = net refundable credits) spread 69 points == SECTION 1 -- the Line 7e units lag == child care/wk order/wk order/yr 7e reads true % of net box 0 1,013 52,662 26.5% 37.7% - 100 1,100 57,221 28.8% 40.9% - 300 1,276 66,340 33.4% 47.4% - 589 1,529 79,506 40.0% 56.9% - 1,290 2,144 111,479 56.1% 79.7% YES Line 7e first reaches 40% at $589/wk of child care (196/child), which is 46% of the $1,290 statutory benchmark. At that point the payor's true burden is 56.9% of net -- a lag of 17 points. == SECTION 2 -- household standard of living (IV.B.13) == no child care payor keeps $ 87,172 recipient household $ 93,821 payor share 48.2% $300/wk child care payor keeps $ 73,493 recipient household $ 91,900 payor share 44.4% Per person the payor still leads: $87,172 for one against $23,455 each for four. State this. == SECTION 4 -- who funds claimed child care == claimed by recipient $15,600/yr ($300/wk) increase in the order $13,678/yr ($263/wk) payor's 6b allocation 87.68% (= recipient's 3c is 12.32%; payor's 3c is 87.68%) share of the expense funded by the payor via the order: 88% == SECTION 5 -- the shared-parenting differential == Box 2 (children reside with A ~2/3 of the time) $1,088/wk ($56,571/yr) Box 1 (shared equally) $1,013/wk ($52,662/yr) difference 6.9% = $3,909/yr for moving from about one third of the parenting time to half of it. Mechanism (CJ-D 304 6f/6g): at Box 2 the payor's column carries 0 children, so Table B = 0.00 and 6g reduces to the difference in income shares. No parenting-time quantity enters the arithmetic at any line. == SECTION 5 -- the shared-parenting adjustment across income disparity == payor 3c Box 2 Box 1 reduction 56.3% 934 209 77.6% 60.8% 958 340 64.5% 66.0% 985 478 51.5% 70.9% 1,010 596 41.0% 76.6% 1,040 826 20.5% 83.3% 1,069 949 11.2% 87.7% 1,088 1,013 6.9% 91.2% 1,103 1,075 2.6% 95.8% 1,123 1,108 1.3% Same children, same equal-parenting arrangement. Only the other parent's income varies. No parenting-time quantity enters any line of the worksheet. == SECTION 5.1 -- Box 3 (split): identical care, different box == Box 1 shared 50-50 of 2 children $ 835/wk (payor: 2 x 50% = 1.0 child-share) Box 3 one child residing with each $ 581/wk (payor: 1 x 100% = 1.0 child-share) difference 30.4% = $13,203/yr driver: 6g nets the columns on the ONE-child schedule. TableB(1)/TableB(2) = 0.714 but a split DESTROYS the economies of scale Table B exists to capture: combined factor across two homes is 2.00 vs 1.40 in one home (+43% more expensive). 3 children, split A=2 B=1: $840/wk vs Box 1 $1,013 (17.0% lower) 3 children, split A=1 B=2: $576/wk vs Box 1 $1,013 (43.1% lower) == SECTION 2 -- child care ignores the parenting box; the payor's own credit is clipped == recipient pays $300/wk: payor's 6b share $263.05/wk under Box 1, $263.05 under Box 2 (identical; no parenting-time term) payor pays $300/wk himself, Box 2: order falls $36.95/wk (12.3% of face value) payor pays $300/wk himself, Box 1: order falls $5.19/wk (1.7% of face value) clip factor under Box 1 = recipient 3a / payor 3a = 537/3822 = 14.0% == SECTION 2.1 -- BOTH parents pay child care under equal shared parenting == The realistic 50-50 case: each parent needs care during their own parenting time. neither pays child care order $ 1,013/wk 7e 26.5% he keeps $ 87,172 she holds $ 93,821 his share 48.2% order+his own care = 37.7% of his net only the recipient pays $300/wk order $ 1,276/wk 7e 33.4% he keeps $ 73,493 she holds $ 91,900 his share 44.4% order+his own care = 47.4% of his net BOTH pay $300/wk order $ 1,271/wk 7e 33.2% he keeps $ 58,163 she holds $ 91,630 his share 38.8% order+his own care = 58.4% of his net Combined child care across both households: $31,200/yr borne by the payor: $ 29,008 (93%) borne by the recipient: $ 2,192 (7%) The payor's OWN $15,600 of child care reduces the order by $270/yr -- the Line 6e clip. CAVEAT, state it: per person the payor still leads -- $58,163 for one against $22,907 each for four. == CAVEATS THAT TRAVEL WITH EVERY FIGURE == 1. Per person the payor leads. Say it before the household comparison. 2. $430/child is a statutory ceiling, not a typical amount. Lead with the $589/wk trigger point, never the $1,290 maximum. 3. One worked example is not a distribution. The frequency of claimed child care near the benchmark is unknown -- which is why the submission supports better data collection rather than asserting a prevalence. 4. The MA Child and Family Tax Credit ($440/dependent) requires the child to be UNDER 13. At two under 13 and one aged 13 to 17 exactly 2 of the 3 qualify, which is what the figures above use. Sensitivity across the whole range: 3 child(ren) under 13: -40.3% 2 child(ren) under 13: -38.9% 1 child(ren) under 13: -37.4% 0 child(ren) under 13: -35.9%