The avatar for @andyreagan
Andy Reagan
Senior Data Scientist, MassMutual Lecturer, UC Berkeley MIDS -- PhD Applied Math, Computational Story Lab, UVM MS Applied Math, UVM BS Math, Virginia Tech
Public
Edited
May 23, 2024
1 star
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contribution_narrative = function(year, contributions, inflate=false) {
const contributions_per_kid = contributions.map(d => inflate ? d[year + 1 - min_start_year].yearly_contribution_inflated : d[year + 1 - min_start_year].yearly_contribution);
const total_contribution = d3.sum(contributions_per_kid);
const target_529 = (1 - (utma_fraction / 100) ) * total_contribution;
const target_UTMA = total_contribution - target_529;
const target_UTMA_per_kid = contributions_per_kid.map(d => money(d / total_contribution * target_UTMA));
return `total contributions of ${money(total_contribution)} with 529 contribution of ${money(target_529)}, total UTMA contribution of ${money(target_UTMA)}, and per kid's UTMA of ${target_UTMA_per_kid.join(", ")}`
}
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catchup_529 = catchup_total - catchup_UTMA
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catchup_UTMA = catchup_total * (utma_fraction / 100)
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catchup_total = d3.max([total_contributions_current_year - yearend_savings, 0])
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target_529_current = (1 - (utma_fraction / 100) ) * yearend_savings
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target_UTMA_current = yearend_savings - target_529_current
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target_UTMA = total_contributions_current_year - target_529
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target_529 = (1 - (utma_fraction / 100) ) * total_contributions_current_year
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nextyear_withdrawals_by_kids = contributions_per_kid_starting_now.map(d => d[current_year + 1 - min_start_year].withdrawal)
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nextyear_adjusted_contribution_by_kids = contributions_per_kid_starting_now.map(d => d[current_year + 1 - min_start_year].yearly_contribution)
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nextyear_target_by_kids = contributions_per_kid.map(d => d[current_year + 1 - min_start_year].balance)
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thisyear_withdrawals_by_kids = contributions_per_kid_starting_now.map(d => d[current_year - min_start_year].withdrawal)
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yearend_target_by_kids = contributions_per_kid.map(d => d[current_year-min_start_year].balance)
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kid_balances = yearend_target_by_kids.map(d => d / total_contributions_current_year)
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total_contributions_current_year = d3.sum(yearend_target_by_kids)
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viewof college_years = Inputs.input(4)
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money = d3.format("$,.0d")
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kids = {
var tmp = {};
for (var i=0; i<kids_dynamic.elements.length; i++) {
if (i % 2 == 0) {
tmp[`Kid ${i/2+1}`] = {birth_year: kids_dynamic.elements[i]};
tmp[`Kid ${i/2+1}`].preschool_start = kids_dynamic.elements[i] + college_years + ( kids_dynamic.elements[i+1] ? -1 : 0 );
}
}
return tmp;
}
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precollege_school_years = 15;
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min_start_year = d3.min(start_years)
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start_years = Object.values(kids).map(d => d.birth_year)
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end_years = Object.values(kids).map(d => d.preschool_start + precollege_school_years + college_years - 1)
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kid_faces = ["🧒","🧒","🧒","🧒","🧒","🧒","🧒","🧒"]
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max_end_year = d3.max(end_years)
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Inputs.table(tuition_inflated)
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tuition_inflated = {
const net_tuition_inflation = tuition_inflation - inflation_rate;
var tmp = Array(max_end_year - min_start_year + 1);
for (var i=0; i < tmp.length; i++) {
const cal_year = i + min_start_year;
const year_diff = cal_year - current_year;
tmp[i] = {year: cal_year, tuition: Math.pow(1 + net_tuition_inflation/100, year_diff) * tuition};
}
return tmp;
}
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viewof rows = Inputs.table(contributions_per_kid[0])
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contributions_per_kid = Object.values(kids).map((d, j) => compute_contributions(d, j, true, NaN, NaN))
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contributions_per_kid_starting_now = Object.values(kids).map((d, j) => compute_contributions(d, j, false, yearend_savings, kid_balances))
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net_return = return_rate - inflation_rate
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compute_contributions = function(d, j, since_birth, yearend_savings_, kid_balances_) {
const start_year = d.birth_year;
const college_start = d.preschool_start + precollege_school_years;
const end_year = college_start + college_years - 1;
// const total_college_cost = tuition * college_years;
const total_college_cost = d3.sum(tuition_inflated.slice(college_start-min_start_year, end_year-min_start_year+1), d => d.tuition);
const yearly_contribution = total_college_cost / (end_year - start_year + 1);
var tmp = Array(max_end_year - min_start_year + 1);
var balanced = false;
var multiplier = 1;
var heat = .9;
var iteration = 0;
const max_iterations = 100
while (!balanced & (iteration < max_iterations)) {
// console.log('iteration', iteration)
for (var i=0; i < tmp.length; i++) {
const cal_year = i + min_start_year;
const year_diff = cal_year - current_year;
const total_inflation = Math.pow(1 + inflation_rate/100, year_diff);
const total_deflation = Math.pow(1 - inflation_rate/100, year_diff);
const inflation_adjusted_contribution = contributions_match_inflation ? yearly_contribution : total_deflation * yearly_contribution;
const started_college = cal_year >= college_start; // this will turn during the cal year they start
const finished_college = cal_year > end_year; // this will turn on the year they graduate
const in_college = (started_college) & (!finished_college);
const born = cal_year >= d.birth_year;
const age = born ? cal_year - d.birth_year : 0;
tmp[i] = {
name: Object.keys(kids)[j],
year: cal_year,
age_last_bday: age,
yearly_contribution: ((cal_year > current_year) | (since_birth & born)) & (!finished_college) ? inflation_adjusted_contribution * multiplier : 0,
withdrawal: in_college ? tuition_inflated[i].tuition : 0
}
if ((cal_year == current_year) & !since_birth) {
tmp[i].yearly_contribution = yearend_savings_ * kid_balances_[j];
}
tmp[i].monthly_contribution = tmp[i].yearly_contribution / 12;
tmp[i].net = tmp[i].yearly_contribution - tmp[i].withdrawal;
tmp[i].balance = (1 + (net_return / 100)) * (i > 0 ? tmp[i-1].balance + tmp[i].net : tmp[i].net);
tmp[i].yearly_contribution_inflated = tmp[i].yearly_contribution * total_inflation;
}
if (Math.abs(tmp[tmp.length-1].balance) > 20) {
if (tmp[tmp.length-1].balance > 0) {
multiplier = multiplier * (1 - heat);
} else {
multiplier = multiplier * (1 + heat);
}
heat = heat * .9;
} else {
balanced = true;
}
iteration++;
}
return tmp;
}
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require("d3")
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import { clone } from "@mbostock/html-in-markdown"
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import { view } from "@tomlarkworthy/view"
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import { Tangle } from "@mbostock/tangle"
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import { Plot } from "@mkfreeman/plot-tooltip"
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