New on FinoLib · Volume V: Personal Finance
My latest article is now live on FinoLib, the free finance library I write: Mortgage Case Study: Borrowing to the Lender’s Limit, from Volume V: Personal Finance. It is part 2 of a 2-part guide. Read the summary below for the substance of the topic, then continue to FinoLib for the complete treatment.
A closer look
Year ten. One earner is laid off. The emergency fund built in Case One has been partially drawn down for other goals over the years and currently holds about three months of essential expenses, not the original six — a realistic, imperfect starting point, not the textbook ideal.
A worked example
Worked Example — Compare the Scenarios: Stress-Testing Case Three
Input changed Stressed value Monthly draw while benefits last Total runway Unemployment benefits Denied (a quit, or misconduct) $2,112.20 9.2 months Health coverage COBRA at ≈$793 $265.20 12.9 months Fund size One month, $6,500 None 6 + $6,500 ÷ $2,112.20 = 9.1 months Flip point: the fund is untouched while benefits last if they pay at least $2,112.20 × 12 ÷ 52 = $487.43 a week after withholding ($541.59 before it).
Under the hood
Under the Hood: Why Three Months of Expenses Can Last Fifteen
Runway is fund ÷ (essential expenses − income that keeps arriving), not fund ÷ expenses. Assume essential expenses of $6,500 a month, including Case Two’s $3,500.90 PITI, so three months is $19,500. The partner’s take-home pay continues: $2,163.60 × 26 ÷ 12 = $4,687.80. Adding the laid-off spouse to that plan costs an assumed $300 a month, and benefits pay an assumed $600 a week less 10% withholding: $540 × 52 ÷ 12 = $2,340 a month for 26 weeks.
Decision rule
If your employer matches, contribute the match rate from paycheck 1 (6.5). If PITI at today’s lockable rate exceeds 28% of gross income, buy less house or put more down (5.2). If a job ends, runway = fund ÷ (essential expenses − income still arriving); draw only that gap and sell no retirement assets (1.4, 7.1: Why Investing Differs from Saving). When to ignore it: the match waits behind step 1 of 1.8 if essentials are not covered; the 28% line matters less when one income alone covers essential expenses.
The costliest mistake
Assume a mid-year layoff: joint AGI is $66,100 + $33,950 of wages after 401(k) and cafeteria-plan health premiums (including the $300 a month to add the laid-off spouse) + $15,600 of benefits = $115,650, taxable income $83,450. A $20,000 cash-out adds 12% × $17,350 + 22% × $2,650 = $2,665 of tax plus the $2,000 additional tax: $4,665. Left at 7% for 24 years it would be $20,000 × 1.07^24 = $101,447. Draw the fund for the gap instead (6.7: Vesting, Rollovers, and What Happens When You Change Jobs).
Edge Cases: When the Standard Answer Changes
Situation What changes Why Number or rule A new plan auto-enrolls you at 3% Half the match is lost until you raise the rate The default is set by law, not the match IRC §414A: 3%–10% start; match $1,125, not $2,250 (1.5) Leaving the first job after two years Unvested match is forfeited Employer money may vest on a schedule Three-year cliff: lose $4,500; six-year graded: lose 80% × $4,500 = $3,600 (6.7: Vesting, Rollovers, and What Happens When You…
Why It Matters
Net worth still rose through a job loss — not because the job loss didn’t hurt, but because Case One’s defaults had already been compounding for a decade before the shock arrived. This is the entire thesis of this volume in one picture: none of the individual mechanics in Parts 1 through 13 are complicated on their own, but stacked consistently over a working life, they produce a household able to absorb the disruptions Part 11 described.
Recap
Year one runs on defaults: a 6% 401(k) contribution captures the full 50% match from the first paycheck, and $432.72 of each $2,163.60 net paycheck builds the $14,063.40 six-month emergency fund by paycheck 33 before moving on to an HSA, a Roth IRA and a 6.5% 401(k).
More from the article
■File for unemployment — Replaces roughly 40%–50% of the lost wages, up to the state’s weekly cap, for up to 26 weeks in most states; benefits are federally taxable, so the household requests 10% withholding on Form W-4V — 11.4
■Choose health coverage — Checks first whether the laid-off spouse can join the partner’s employer plan, which losing job coverage allows mid-year; otherwise compares COBRA (about $793 a month for single coverage, far more for a family) with the ACA Marketplace, whose subsidy turns on…
■Triage the budget — Immediately re-runs 1.3’s zero-based method on the reduced income, cutting the “wants” category first rather than touching retirement contributions — 1.3
What the full article covers
The full article includes worked examples, a look under the hood at the mechanics, a clear decision rule, the one mistake that costs people the most, a recap, a reveal-on-click quiz and the official sources behind every figure.
Volume V: Personal Finance
Read the full article on FinoLib
The complete article, Mortgage Case Study: Borrowing to the Lender’s Limit, with every worked example, diagram, quiz and source, is free to read in Volume V, Personal Finance on finolib.com.
Explore the Finance Education Series: Vol. II — Capital Markets · Vol. I — Global Economy · Vol. III — Finance Encyclopedia · Vol. IV — Finance Careers · Vol. V — Personal Finance