Kids Allowance Ledger

Overview

A double-entry allowance engine that turns a weekly handout into a money-education system: every deposit auto-splits into Spend / Save / Share jars, the Save jar earns parent-paid interest (or a 401(k)-style match), goals track days-to-purchase, and the ledger produces kid-readable statements. The point is not accounting — it is making compound growth, delayed gratification, and trade-offs visible to a 6–16 year old.

When to Use

• Parent asks "how much allowance should I give", "how do I teach my kid to save", "chore chart that pays"
• Setting up jar splits, interest, or a parent match for a child's money
• Answering the kid-classic "when can I buy the PS5?" with a real ETA
• Reviewing what the child earned/spent/saved over a month or year
• Comparing chore-commission vs fixed allowance models

Don't use for: adult budgeting (see debt-blitz-planner), family shared expenses (roommate-rules-referee), or tax-deductible tracking (tax-doc-collector).

Core Model

1. Income events — weekly allowance (fixed) and/or chore commissions (per-task payouts). Both append to the ledger with a date and source.
2. Jar split — each income auto-divides by percentages (default 50 Spend / 40 Save / 10 Share). Percentages are per-child and change with age.
3. Growth engine (choose one or both):
   • Interest mode: monthly % on the Save jar balance (5%/mo ≈ 80%/yr — deliberately exaggerated vs real banks so the curve is felt).
   • Match mode: parent matches Save-jar deposits up to a monthly cap — a literal 401(k) demo.
4. Goals — wishlist items with price; the tool computes weeks-to-goal at the current Save-jar inflow rate and after any match.
5. Spend events — deduct from Spend (or Save with an explicit raid that shows the future value destroyed — the strongest teaching moment in the tool).

Numbered Workflow

1. init the ledger: child name, age, weekly allowance, jar split, growth mode.
2. chore add the commission menu (name → payout), sized against the weekly base.
3. Each week (or live): deposit allowance, earn <chore> payouts.
4. goal add the wishlist with price and link to a jar.
5. Run project --years 3 to show the child the compounding curve.
6. Monthly: statement → kid-readable summary; audit → parent sanity check on raid frequency and Share-jar usage.
7. On birthdays: bump age, widen the Save %, raise the match cap.

Commands

python3 scripts/allowance_ledger.py init --name Mia --age 8 \
  --weekly 5 --split 50/40/10 --interest 5 --match-cap 10
python3 scripts/allowance_ledger.py chore add "walk dog" 1.50
python3 scripts/allowance_ledger.py deposit 5.00 --note "weekly allowance"
python3 scripts/allowance_ledger.py earn "walk dog"
python3 scripts/allowance_ledger.py spend 12.99 --note "comic book" --jar spend
python3 scripts/allowance_ledger.py goal add "LEGO set" 89.99
python3 scripts/allowance_ledger.py project --years 2
python3 scripts/allowance_ledger.py statement
python3 scripts/allowance_ledger.py audit

Store lives in allowance_ledger.json next to the script (override: --store PATH).

Age Banding (guidance baked into references)

Pitfalls

1. Paying for everything — grades, teeth brushing, existing family duties stay unpaid; commissions are for above-baseline work only. The chore menu should exclude "make your bed".
2. Bailing out raids — if a Save raid has no consequence display, the lesson dies. Always show --show-future-cost on Save spends.
3. Realistic interest — 0.1%/mo real-bank rates teach nothing at kid scale; pay generous fake rates and say so ("I'm the bank and I'm inflationary").
4. Split changes mid-week — change splits only at deposit boundaries or the jar math and the child's trust both break.
5. Share jar as decoration — schedule its use (birthday donations, class fundraisers) or kids learn charity is a shelf.

Example

8-year-old, $5/week, 50/40/10, 5%/mo interest on Save, $90 LEGO goal: the Save jar nets $2/wk + interest; project shows ≈ $125 by month 12 and the goal ETA slips from 45 weeks to 34 once a 50% match up to $10/mo is switched on — the kid sees the match, not the parent, close the gap.