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+# Parameter value sources and justification
+Updated for phase 1 calibration as of April 28th, 2026
+
+## Parameter Descriptions
+
+| Parameter                     | Description                                                                                     |
+|-------------------------------|-------------------------------------------------------------------------------------------------|
+| `infectiousness_rate_fn` | Constant rate of infection attempts generated by each infectious individual over the duration of infectiousness                     |
+| `symptomatic_reporting_prob` | the probability that an infectious individual that is currently symptomatic is reported upon being imported into the population                     |
+| `probability_mild_given_infect` | Probability a person develops any symptoms given that they were infected. Equivalent to one minus the asymptomatic probability.                     |
+| `probability_{symptom_B}_given_{symptom_A}` | Probability a person with symptom category A  transitions to the next ordered symptom severity category B, stratified by age group.                     |
+| `{symptom_A}_to_{symptom_B}_delay`      | Log-normal delay distribution parameters for the transition from symptom cateogry A to symptom category B, given that the individual is selected to progress along the illness severity timeline.     |
+| `{symptom_A}_to_resolved_delay`  | Log-normal delay distribution parameters for the transition from illness with symptom category A to resolution.|
+| `settings_properties`         | Properties of settings, including the density-dependence scaling factor (`alpha`).             |
+| `itinerary_ratios`            | Default proportion of time individuals spend in specific setting categories.                   |
+| `prevalence_report`           | Configuration for the prevalence report, including whether to write, filename, and period.     |
+| `incidence_report`            | Configuration for the incidence report, including whether to write, filename, and period.      |
+| `transmission_report`         | Configuration for the transmission report, including whether to write and filename.            |
+| `aggregated_deaths_report`    | Configuration for the aggregated deaths report, including whether to write, filename, and period.|
+| `first_death_terminates_run`  | Boolean indicating whether the simulation terminates upon the first observed death.            |
+
+## Parameter Values
+
+| Parameter                     | Value or Prior                                                                                         | Value Source |
+|-------------------------------|------------------------------------------------------------------------------------------------|--------------|
+| `infectiousness_rate_fn (rate)` | `LogNormal (mean -1.5, std_dev 0.5)`                                                                          |       Scaled to duration in order to produce an $R_0$ of approximately 2.1       |
+| `infectiousness_rate_fn (duration)` | `12.0`                                                                          |      Generation interval maximum        |
+| `symptomatic_reporting_prob` | `Beta (alpha 5, beta 5)`                                                                          |      Perkins et al. 2020        |
+| `probability_mild_given_infect` | `Beta (alpha 7, beta 3)`                                                                          |       Reasonable prior belief that 60%-80% of individuals will develop symptoms       |
+| `probability_dead_given_critical (Age0To17)` | `0.026`                                                                          |     CDC COVID-19 scenarios documents         |
+| `probability_dead_given_critical (Age18To49)` | `0.111`                                                                         |       CDC COVID-19 scenarios documents       |
+| `probability_dead_given_critical (Age50To64)` | `0.292`                                                                         |       CDC COVID-19 scenarios documents       |
+| `probability_dead_given_critical (Age65Plus)` | `0.699`                                                                         |        CDC COVID-19 scenarios documents      |
+| `critical_to_dead_delay (mu)` | `2.565`                                                                                      |      CDC COVID-19 scenarios documents        |
+| `critical_to_dead_delay (sigma)` | `0.814`                                                                                   |       CDC COVID-19 scenarios documents       |
+| `critical_to_resolved_delay (mu)` | `2.565`                                                                                 |       CDC COVID-19 scenarios documents       |
+| `critical_to_resolved_delay (sigma)` | `0.814`                                                                              |         CDC COVID-19 scenarios documents     |
+| `settings_properties (Home)`  | `Uniform(0, 1)`                                                                             |      No prior belief on at-home density-dependent transmission        |
+| `settings_properties (Work)`  | `{"alpha": 0.0}`                                                                             |      No density-dependent transmission outside the home        |
+| `settings_properties (School)` | `{"alpha": 0.0}`                                                                            |      No density-dependent transmission outside the home        |
+| `settings_properties (Community)` | `{"alpha": 0.0}`                                                                        |    No density-dependent transmission outside the home          |
+| `itinerary_ratios (Home)`     | `0.25`                                                                                       |       Preliminary value to split time evenly across settings       |
+| `itinerary_ratios (Work)`     | `0.25`                                                                                       |       Preliminary value to split time evenly across settings       |
+| `itinerary_ratios (School)`   | `0.25`                                                                                       |        Preliminary value to split time evenly across settings      |
+| `itinerary_ratios (Community)` | `0.25`                                                                                      |          Preliminary value to split time evenly across settings    |