MATHANICS®

Mathanics · economic transmission simulator

Follow the transmission · where the pressure lands and where it bites

The economy is not a calculator. It is a transmission system. Set up the scenario, then read how the shock travels.

Bank rate ↑25bps · 0.00% → 0.25%Whole economyeveryday
Shock signaturePressure shape

The price of money rises.

FromCentral bankCost of borrowing turns up
Lands onHousehold borrowers and Indebted businesses

Pressure · Borrowers and debt-heavy firms.

OffsetSavers may gain, late and unevenly.Savers and depositors

Inequality tilt · Debt and weak buffers feel the squeeze before cash does.

Lever· Q0 — initial shockPressure impulse

Bank rate ↑25bps · 0.00% → 0.25%

0.00%0.25%
Horizon focus · immediate repricing · variable-rate · market channelsTheory emphasis · demand · expectations · output gap

What changed · Mostly fixed mortgages · borrower cashflow exposure is back-loaded; refinancing cliffs matter later.

Bank rate ↑25bps · 0.00% → 0.25% — borrowing gets more expensive; some households and firms feel it sooner than others.

£1 of first-round pressure · engine-adjusted allocation

Pence remain qualitative weights. The engine shifts emphasis when assumptions change; this is not a forecast or money flow.

Think of the £1 as a spotlight: bigger shares show where the shock lands hardest under these assumptions — not money received.

What changed · mostly fixed mortgages · strong household buffers · slow bank pass-through → Household borrowers -15p (base 45p); Financial markets +15p (base 10p).

30p
20p
20p
5p
25p
  • Household borrowersadjusted -15p30p

    base: 45p

    Mostly fixed mortgages — Q0 household cashflow exposure is back-loaded; refinancing cliffs matter later, not now. Strong household buffers — immediate household stress slightly absorbed.

  • Business borrowers20p

    Floating-rate corporate debt reprices quickly; smaller firms feel it first. Pressure share, not money received.

  • Banks · marginadjusted +5p20p

    base: 15p

    Slow pass-through — bank net interest margin widens for longer.

  • Savers · partial offsetadjusted -5p5p

    base: 10p

    Slow bank pass-through — deposit relief delayed; saver offset shrinks.

  • Financial marketsadjusted +15p25p

    base: 10p

    Mostly fixed mortgages — signalling and curve repricing carry more of the Q0 work. Strong buffers — more of Q0 sits in market and signalling channels rather than household cashflow.

Where did the £1 go?

Teaching £1 composition: share of each £1 of pressure within its class. Values never exceed 100p.

Snapshot 0.2× baseline (17p vs 100p)Snapshot · 0.2× baseline · 17p vs 100p

Teaching assumptions, not empirical forecasts.

Note on central-bank flows: Bank Rate interest paid by the central bank to commercial banks, and any APF indemnity from Treasury that funds it, are sequential legs of the same Bank Rate operating cost of the central-bank balance sheet — not two independent public costs.

Pressure created by each lever

scenario totals, gross LEDGER
  • Bank Rate52p pressure created
    48p received elsewhereLedger balances

Balanced does not mean harmless: ledger flows net to zero because payments are received somewhere else.

Distributional Tilt

Asset-holder benefit · household / company pressure

Not a Gini measure. A directional lens from this scenario's flows.
  • Household / company / service pressure

    Blended household: mortgagors, renters, savers and low-income households differ.

    +5p
  • Public-sector fiscal pressure

  • Asset-holder income (cash)

    Institutional asset holders: effects may pass through to pension members and policyholders over time, not as direct household cash.

    −6p
  • Asset-holder valuation (mark-to-market)

    Valuation pressure on gilt / asset holdings. Not cash today.

  • External — trade leakage

    Cash paid abroad for imports (e.g. energy).

  • External — financial (coupons / interest)

  • Asset-swap / liquidity shift

    QE / QT exchange cash for gilts (or vice versa). The cash leg is shown; the gilt leg of equal size is not a gain or loss.

Central-bank flows are system bookkeeping and excluded from the tilt. Buckets read from canonical LEDGER / VALUATION rows; QE/QT cash legs are reported as asset-swap, not as ordinary income or leakage.

LEDGER

Money flows — teaching £1 split

Share of each teaching £1 of pressure that lands as a real cash flow. Ledger items must balance across the system.

  • Bank net money in(gross +4p / −25p)+21p
  • Household net money out(gross +14p / −4p)11p
  • Government net money out11p
  • Company net money out7p
  • Central bank net money out(gross +4p / −4p)0p
  • Rest of world net money in+4p
VALUATION

Valuation effects — teaching £1 split

Share of each teaching £1 of pressure that shows up as a price revaluation.

  • Pensions & insurers net pressure+11p
GAUGE

Pressure gauges — teaching £1 split

Share of each teaching £1 of pressure that builds as a teaching signal (risk, confidence, capacity).

  • Company net pressure+7p
  • Pensions & insurers net pressure+4p
  • Rest of world net pressure+4p

Only ledger items have to balance. Valuations and gauges show pressure, risk or market movement. Values shown are composition share of £1. In the default teaching split, each Money-flows row equals the share of £1 shown on the matching Flow Map actor tile.