The Economics of Living Together

C01

For two Gauteng adults bringing home R30,000 and R20,000 a month, combining households at 25 rather than 35 leaves about R3.972 million more combined household wealth at 75 in the average scenario, in constant 2026 rand. The direct living-cost saving is about R1.059 million. The larger gap comes from investing that earlier saving and from avoiding expensive negative balances.

GSX:HH-001:C01 · Modelled · Conditional · high sensitivity · Version 1.0

Depends on

A01Two Gauteng earnersThe household is two adults in Gauteng with take-home pay of R30,000 and R20,000 a month. The results are combined household wealth, not each person's legal ownership.high sensitivity

A02Ten-year difference in household timingThe Early couple combines adequate households at 25. The Later couple combines them at 35. From 35 onward the model gives both the same housing arrangement, income, expenses, shocks, and retirement assumptions.high sensitivity

A03Average-case returns and costsIn the average case, real salary growth and real living-cost growth are both 0.75% a year. The net real investment return is 3% a year after fees and tax drag. The initial monthly cohabitation dividend is R8,500.high sensitivity

A04Surplus is investedThe model invests the available surplus. It does not spend that surplus on a higher lifestyle.high sensitivity

Modelled results cited

R01Average case, age 75, early consolidation minus later consolidationIn the average case, the Early household holds R3.972 million more combined wealth at 75 than the Later household, in constant 2026 rand.modelled

R02Average case, lifetime living costs and age-35 leadIn the average case, the Early household spends about R1.059 million less on living costs over the model. At 35, before the later years are financially identical, its lead is R1.188 million.modelled

Registered supporting sources

The Economics of Living Together · GSX:HH-001:PDF