Table 1.
Parameter values for agent-based simulations
| Parameters | Values | Notes | Robustness test number |
| Network structure (environment), overall | |||
| Number of agents (humans) | 10,000 | ||
| Number of sectors | 8 | ||
| Number of categories in network ties | 3 | Family, close, and weak ties | 5 |
| Consideration of family ties | Yes | All of the time | |
| Consideration of close ties in nonfamily sectors | Yes | No in a robustness test | 5 |
| Consideration of weak ties in nonfamily sectors | Yes | No in a robustness test | 5 |
| Consideration of the consolidation of social space | No | Yes in a robustness test | 11 |
| Social network model for family ties | Complete | ||
| Social network model for close ties | Small-world (61) | Addressing consolidation in social space | |
| Rewiring probability in the small-world model | 0.2 | 4 | |
| Social network model of weak ties | Complete | See the edge weight below | |
| Detailed parameters for the eight sectors (for the edge weights) | |||
| Numbers of groups in families, workplaces, educational institutions, healthcare institutions, grocery stores, restaurants/cafés, sports/leisure, and the other sectors | (3,000, 1,000, 25, 25, 10, 25, 500, 500) | Based on a sample city | 1 |
| Enrollment rates for families, workplaces, educational institutions, healthcare institutions, grocery stores, restaurants/cafés, sports/leisure, and the other sectors | (1, 0.4, 0.25, 0.5, 0.5, 0.5, 0.7, 0.5) | Workplace: 40% of individuals engage in working (62, 63); Sports/leisure (64) | |
| Distribution used for the group assignment | Uniform | Geometric distribution in robustness tests | 3 |
| Number of close ties in workplaces, educational institutions, healthcare institutions, grocery stores, restaurants/cafés, sports/leisure, and the other sectors | (Up to 6, up to 4, 0, 0, 0, up to 8, up to 4) | Based on refs. 40 and 42; vary due to the group size and rewiring of network ties; when group size is smaller than the number (e.g., six for workplaces), all of the possible network ties were made | |
| Edge weight of families | 1 | Default value | |
| Edge weight of close ties in nonfamily sectors | 0.5 | Transmissibility of close ties is a half of that of family members [intensity of 0.5 (46) × encounter frequency of 1] | 5 |
| Edge weights of weak ties in workplaces, educational institutions, healthcare institutions, grocery stores, restaurants/cafés, sports/leisure, and the other sectors | (0.075, 0.075, 0.0025, 0.005, 0.01, 0.025, 0.025) | Intensity of 0.1 (46) × encounter frequency of (0.75, 0.75, 0.025, 0.05, 0.1, 0.25, 0.25) | 5 |
| Strategy-specific settings | |||
| Exceptions in the lockdown strategies, sector | Healthcare | Healthcare sector is not closed | |
| Exceptions in the lockdown strategies, group size | No | Only in a robustness test: groups with a small group size are not closed (avoid large gatherings) | 10 |
| Fraction in division in the dividing strategy | 0.5 (even) | A robustness test for the noneven split | 2 |
| Infectious disease dynamics | |||
| Initial number of infections on day 0 | 10 | The number of initially infected individuals, located randomly in the social networks | |
| Number of spontaneous infections on week X | 0 | New infections at day 7, 14, 21, … | 9 |
| Per-contact transmissibility (β) | 0.04458 | Converted from R0 of 2.5 (see Converting R0 to β for Agent-Based Simulations) (38, 45) | 6 |
| Latent period (duration in the days in the “Exposed” compartment) | 3 d (39) | ||
| Infectious period (mean duration in the “Infectious” compartment) (τ) | 3 d (38, 39) | Used as the mean of a geometric distribution | 7 |
| Observation period in the simulation | 300 d | ||
| Symptoms and behavior (agents) | |||
| Behavioral strategy updates | None | Considered in a robustness test | 8 |
| Contacts during self-isolation of symptomatic cases | Family only | Considered in a robustness test | 8 |
| Asymptomatic ratio | 0.45 (65) | Considered in a robustness test | 8 |
| Viral shedding and transmissibility of asymptomatic cases | Same as symptomatic cases (0.04458) | Constant; see refs. 66 and 67 | |
| Presymptomatic period | 0.5 (half of the infectious period) (68) | Considered in a robustness test; 0.5 is used as a parameter for p in a binominal distribution | 8 |