Market Heatmap

One point of difference between demand and supply swings the salary effect by half

Demand 6 against supply 6 is treated as an unfavourable market and the salary impact is multiplied by 0.8. Demand 7 against the same supply of 6 is favourable, and the multiplier jumps to 1.2. That single point moves the result by a factor of 1.5, because the model tests whether the balance is above zero rather than how far above.

How it works

• Compares your rating of demand for a skill with your rating of the supply of people who have it.
• Scores the market, counting demand at twice the weight of supply.
• Adjusts an expected salary effect up or down depending on which side of zero the balance falls.

balance = demand − supply
market score = demand × 10 − supply × 5
adjusted impact = salary impact × 1.2 if balance > 0, otherwise × 0.8

Worked example

Demand and supply both rated 6, then demand raised to 7.

1. 6 against 6: balance = 0, market score = 60 − 30 = 30, multiplier 0.8
2. 7 against 6: balance = 1, market score = 70 − 30 = 40, multiplier 1.2
3. the multiplier changes by 1.2 ÷ 0.8 = 1.5 across that single point
4. an exact tie counts as unfavourable, since the test is strictly greater than zero
5. demand is weighted at 10 per point and supply at 5, so demand counts double

The market score moves smoothly from 30 to 40, but the salary multiplier does not move smoothly at all — it steps. Two ratings a single point apart give answers half as far apart again.

Reading the result

• A threshold test throws away the size of the gap. Demand 10 against supply 1 and demand 7 against supply 6 receive exactly the same 1.2 multiplier, even though one describes a severe shortage and the other a mild one.
• An exact tie is treated as unfavourable rather than neutral, because the comparison is strictly greater than zero. If you have rated both sides the same because you genuinely do not know, expect the pessimistic branch.
• Both inputs are your impressions, and impressions of supply are usually the weaker of the two. You see the roles advertised far more clearly than you see the other candidates applying for them, which tends to make supply look lower than it is.
• Real markets are local and specific. National demand for a skill tells you little about the twenty employers within commuting distance of you, and this model has no way to represent that.

Common questions

Why does demand count double against supply?

The market score weights demand at 10 per point and supply at 5, a deliberate choice that treats a shortage of roles as the bigger constraint. It is a convention rather than a measurement, so read the score as a ranking device between skills you are comparing.

What happens if demand and supply are equal?

You get the unfavourable multiplier of 0.8, because the test requires the balance to be strictly above zero. A tie is not treated as neutral, which is worth knowing if you tend to rate both sides the same when uncertain.