Table 2 Prior distributions for the Bayesian statistical model.

From: Model-based evaluation of school- and non-school-related measures to control the COVID-19 pandemic

Parameter

Priora

Explanation

ϵ

Uniform (0, 1)

Flat prior

α

InvGamma (32.25, 9.75)

99% of the prior density of 1/α between 2 and 5 days

γ

InvGamma (22.6, 2.44)

99% of the prior density of 1/γ between 5 and 15 days

ν[0, 20), ν[20, 30)

  

ν[30, 40), ν[40, 50)

folded-\({\mathcal{N}}(0,5)\)

Vague prior

ν[50, 60), ν[60, 70)

  

ν[70, 80), ν80+

  

β[0, 20)b

Lognormal (−1.47, 0.1)

Log-odds \(-1.47=\mathrm{log}\,(0.23)\) based on prior estimates8

β[20, 60)b

Lognormal (−0.45, 0.1)

Log-odds \(-0.45=\mathrm{log}\,(0.64)\) based on prior estimates8

r

Lognormal(5, 2)

Vague prior

ζ1

\({\mathcal{N}}(1,0.1)\)

A priori, we expect the reduction in contacts after the first lockdown to account for most of the decrease in the transmission rate

t1

\({\mathcal{N}}(23,7)\)

The mean of t1 is given by the day of initiation of most drastic social distancing measures (15 March); most measures were taken within two weeks from this date

K1

\({\rm{Exp}}(1)\)

For K1 = 1 the uptake of measures takes approximately 6 days

θ

Uniform (10−7, 5 × 10−4)

Vague prior allowing for approximately 100–105 infections at time t0

  1. aThe scale parameter of the normal and log-normal distributions is equal to the standard deviation.
  2. bβ60+ = 1 for the reference group of 60+.