Measure one purchase, then check the wider basket
What does an affordable-burger count actually tell you?
The separate scenario result divides modeled monthly take-home by an entered burger price and rounds down to whole burgers. It measures buying capacity for one supplied product, not an entire household budget. The timeline uses fixed historical fixtures and shows the same interpolated snapshot in both panels.
The prices, flat 18% tax assumption and supplied source counts are not independently validated here. The model assumes 52 paid weeks, excludes other expenses and does not calculate payroll taxes or benefits. Its fixed historical index does not respond to your scenario inputs.
Try a worked example
Reset to the supplied 1985 preset: $3.35 × 40 × 52 ÷ 12 = $580.67 monthly gross. Applying the model’s 18% tax leaves $476.15; dividing by $1.60 and rounding down gives 297 whole burgers. Change weekly hours to 20 and tax to 0, then leave the input: the scenario becomes $290.33 and 181 burgers. Export JSON to retain these inputs and the separate scenario calculation.
Keep the scenario separate from the timeline
The scenario reads wage, hours, tax and price. The timeline and historical index retain fixed fixtures; dragging the timeline interpolates between those fixtures rather than retrieving prices for the selected year. Replay and Reset remain available. The export distinguishes entered parameters, scenario results and historical fixtures.
Use a price index for broader purchasing power
BLS explains how ratios of CPI indexes translate amounts between years and express purchasing power in constant dollars. That comparison uses a broader consumer-price measure. A change in burger affordability alone cannot establish the change in all living costs. Choose matching periods and state which measure you used. BLS: purchasing power and constant dollars
Explain the rounding and assumptions
Whole-burger counts round down; the fixed index is a ratio of rounded historical counts. Small price changes can therefore leave a count unchanged and then make it jump. Changing hours or the flat tax percentage creates a hypothetical income calculation, not an estimate of an actual worker’s withholding or disposable income.
Sources and further reading