Monte Carlo Analysis: Core Reform vs Ancillary Schemes

The same simulation, run thousands of times with randomised economic shocks and varied parameters, to test whether the structural finding holds across a wide range of assumptions.

What you're looking at. Each of the four scenarios below (Status Quo, Ancillary Only, Core Reform, Both) runs the same 900-farm, 60-year simulation 2,000 times over, with a random economic shock each year and every parameter redrawn within a plausible range each run. Instead of showing one run, the charts show the spread of outcomes across all 2,000: how much the result varies depending on which shocks happened to land and which assumptions applied. A scenario that stays reliable across thousands of runs is a stronger finding than one that only works in a single lucky run. Click Run Analysis to see the result.

Final outcomes at year 60

Distribution across all runs. Box = interquartile range (middle 50% of runs). Line = median. Whiskers = 5th–95th percentile.

Status Quo
Ancillary Only
Core Reform
Both
What to notice:
Full read-out — available in a working session

Trajectories over time

Solid line = median across all runs. Shaded band = interquartile range (middle 50%).

Status Quo
Ancillary Only
Core Reform
Both
What to notice:
Full read-out — available in a working session

Summary statistics

Median values at year 60, with interquartile range in brackets.

Scenario Soil Quality Biodiversity % Good Practice
What to notice:
Full read-out — available in a working session
Method. Farms make economically rational decisions each year based on the incentive structure they face, and soil and biodiversity respond with realistic asymmetry — degradation faster than recovery.
Full method and parameter definitions — available in a working session
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