Relationships and pair formation

The following parameters determine how individuals form relationships, such as sexual behavior, relationship duration, age gaps, and any gender differences in those characteristics.

Note

Parameters are case-sensitive. For Boolean parameters, set to 1 for true or 0 for false. Minimum, maximum, or default values of “NA” indicate that those values are not applicable for that parameter.

EMOD does not use true defaults; that is, if the dependency relationships indicate that a parameter is required, you must supply a value for it. However, many of the tools used to work with EMOD will use the default values provided below.

JSON format does not permit comments, but you can add “dummy” parameters to add contextual information to your files. Any keys that are not EMOD parameter names will be ignored by the model.

Parameter

Data type

Minimum

Maximum

Default

Description

Example

Coital_Dilution_Factor_2_Partners

float

1.19E-0

1

1

The multiplicative reduction in the coital act rate for all relationship types when an individual has exactly two current partners. Represents coital dilution.

{
    "Coital_Dilution_Factor_2_Partners": 0.5
}

Coital_Dilution_Factor_3_Partners

float

1.19E-0

1

1

The multiplicative reduction in the coital act rate for all relationship types when an individual has exactly three current partners. Represents coital dilution.

{
    "Coital_Dilution_Factor_3_Partners": 0.33
}

Coital_Dilution_Factor_4_Plus_Partners

float

1.19E-0

1

1

The multiplicative reduction in the coital act rate for all relationship types when an individual has exactly three current partners. Represents coital dilution.

{
    "Coital_Dilution_Factor_4_Partners": 0.45
}

Enable_Coital_Dilution

boolean

0

1

1

Controls whether or not coital dilution will occur.

{
    "Enable_Coital_Dilution": 1
}

Min_Days_Between_Adding_Relationships

float

0

365

60

The minimum number of days between adding two consecutive relationships as a means to control concurrency. The constraint does not apply if an individual breaks an existing relationship.

{
    "Min_Days_Between_Adding_Relationships": 1
}

PFA_Burnin_Duration_In_Days

float

1

3.40E+38

365000

The number of days to continue tuning the pair formation rates. After this duration, the rates will remain at the last rate value calculated.

{
    "PFA_Burnin_Duration_In_Days": 5475
}

PFA_Cum_Prob_Selection_Threshold

float

0

1

0.2

This parameter serves to minimize the extent to which relationships with unlikely age gaps are formed. These unlikely relationships could be generated due to lack of diversity in the PFA. Within the algorithm, males pick from amongst the available females by age bin, weighted by the conditional of the joint_probability matrix given the male age bin. If the sum of the probabilities in the female age bins that are not empty is below this threshold, the male will wait till the next update. Setting this parameter to a value near 1 dramatically increases the delay that individuals will experience in seeking relationships. Setting this parameter to 0 disables the feature.

{
    "PFA_Cum_Prob_Selection_Threshold": 0.4
}

Sexual_Debut_Age_Female_Weibull_Heterogeneity

float

0

50

20

The inverse shape of the Weibull distribution for female debut age.

{
    "Sexual_Debut_Age_Female_Weibull_Heterogeneity": 0.05
}

Sexual_Debut_Age_Female_Weibull_Scale

float

0

50

16

The scale term of the Weibull distribution for female debut age.

{
    "Sexual_Debut_Age_Female_Weibull_Scale": 15.919654846191
}

Sexual_Debut_Age_Male_Weibull_Heterogeneity

float

0

50

20

The inverse shape of the Weibull distribution for male debut age.

{
    "Sexual_Debut_Age_Male_Weibull_Heterogeneity": 0.05
}

Sexual_Debut_Age_Male_Weibull_Scale

float

0

50

16

The scale term of the Weibull distribution for male debut age.

{
    "Sexual_Debut_Age_Male_Weibull_Scale": 16.946729660034
}

Sexual_Debut_Age_Min

float

0

3.40E+38

13

The minimum age at which individuals become eligible to form sexual relationships.

{
    "Sexual_Debut_Age_Min": 13
}