Table B1.
Variable Construction Details
| Variable (Original Variables) | Details |
|---|---|
| Academic Outcomes | |
| GPA (H1ED11/12/ 13/14) | Average letter grades on 4-point scale. |
| PVT (AH_PVT) | Add Health Peabody Picture Vocabulary Test |
| Behavioral & Attitudinal | |
| Substance Use (H1TO5/10/18/32/ 36/39/42) | Max(H1TO 5,10) + 2* H1TO 32 + 2* H1TO18 + 3*Max(H1TO36,39,42). Indicator variables for tobacco, marijuana, alcohol, and illegal drug use respectively. |
| Delinquency (H1DS1/2/4/7/ 8/9/10/12/13) | Average of indicator variables for: grafitti, property damage, stealing, running away, driving cars without permission, stealing >$50, breaking and entering, selling drugs, and stealing <$50. |
| Violence (H1DS5/6/11/14, H1FV5/7/8/9) | Standardized Chronbach's scale. In last 12 months: serious physical fights, hurting someone, use/threaten weapon, group fighting, any fighting, ‘pulling’ weapons, using weapons, carried weapon to school. |
| School Effort (S48) | In general, how hard do you try to do your school work well? 1= “I try very hard to do my best,” 0=otherwise. |
| Parental Aspirations (H1WP11, H1WP15) | Sum of 1-5 scaled measures of how disappointed each parent would be if student did not attend college. |
| College Aspirations (H1EE1) | On a scale of 1 to 5, where 1 is low and 5 is high, how much do you want to go to college? |
| College Probability (H1EE2) | On a scale of 1 to 5, where 1 is low and 5 is high, how likely is it that you will go to college? |
| No Breakfast (H1GH23J) | Indicator variable for usually having nothing for breakfast. |
| Extracurricular Activities | |
| All Clubs (S44A1-33) | Count of all club/organization/sport participation in in-school questionnaire. Same as Acad. Clubs, plus: cheerleading/dance team, chorus/choir, other club, and all sports. |
| Academic Clubs (S44A1-13, S44A16, S44A30-33) | Count of organization participation with intellectual components: Languages, Book, Computer, Debate, Drama, FFA, History, Math, Science, Band, Orchestra, Newspaper, Honor Society, Student Council, Yearbook. |
| Network Structure | |
| Density (AXSDENS) | Di = ΣS/s(s-1), the proportion of ties between friends which are observed in the ego-network. |
| Centrality (BCENT10X) | Bonacich centrality score for ego-network. |
| Popularity (IDGX2) | Number of friendship nominations received. |
| Network Content | |
| Interactions (S34[A-E]-S43[A-E]) | Sum of friend-specific dichotomous indicators of interactions: went to their house; hung out after school; spent time together last weekend; talked about a problem in last week; talked on telephone in last week. |
| School Effort (AXSS48) | Average of friends’ response to, “In general, how hard do you try to do your school work well?” Scaled 1 to 4. |
| School Difficulty (AXSS46[A-D]) | Average of friends’ ratings of different difficulties – with teachers, paying attention, doing homework, getting along with other students. |
| Delinquency (AXSS59A-G) | Sum of friends’ avg. responses (scaled 0 (“never”) to 6 (“nearly everyday”): smoking, drinking, getting drunk, racing, dangerous behaviors, lying to parents, skipping school, getting in fights |
| Race Heterogeneity (EHSRC5) | HiA = 1-[∑1n (Rk/en)2], where Rk is count of nodes with race k in ego-network, en is nodes with valid data for race, and n is the total racial categories in the network. |
| Age Heterogeneity (EHSAGE) | HiA = 1-[∑1n (Ak/en)2], where Ak is count of nodes with age k in ego-network, en is nodes with valid data for age, and n is the total age categories in the network. |
| College Probability (AXSS45E) | Average of nominated friends’ self-rated probability of attending college, scaled 0-8. |
| Middle Class Probability (AXSS45F) | Average of nominated friends’ self-rated probability of attaining a middle-class income by age 30, scaled 0-8. |
| Demographics & Family Structure | |
| Age (H1GI1M, H1GI1Y, IMONTH, IYEAR) | Difference in Student-reported date of birth and interview date, in years |
| Full Siblings† (H1HR3A-T) | From household roster. |
| HH Female† (H1HR2A-T) | From household roster. Count of female siblings. |
| Birth Order† (H1HR15) | From household roster. =1 if first-born and increases thereafter. |
| HH Size† (H1HR2) | From household roster. Count of household residents. |
| Non-White (H1GI4, H1GI6) | =1 if not white or hispanic; =0 otherwise |
| Parents Married (PA10) | Parental-report; =1 if biological parents married; =0 otherwise. |
| Sibling Age SD† (H1HR[7/8]A-T) | From household roster. Standard deviation of full sibling ages. |
| Immigrant (H1GI11) | =1 if born outside U.S.; =0 otherwise |
| Neighborhood Characteristics | |
| Bad Neighborhood (PA33-34, H1IR10-11, H1IR14-15) | Weighted sum of following indicators: Litter is a problem (parent-report; weight=1), drug dealers/users are a problem (parent-report; weight=2), family doesn't live in single-unit home (interviewer-report, weight=1), house is not very well kept (interviewer-report, weight=1), buildings on street poorly or very poorly kept (interviewer-report, weight=1), interviewer felt concerned for safety in neighborhood (weight=2). |
| Home Value Disp. (BST90P28) | Contextual data. Tract-level variation in value of homes. |
| Social Capital (PA31-32) | Parental-report. Sum of responses (recoded – 1=definitely/probably/might not; 2=probably would, 3=definitely would): how likely tell neighbor if their child getting into trouble, how likely neighbor tell you if child in trouble. |
| Unemployment (BST90P23) | Contextual data. Tract-level unemployment rate. |
| Urban (BST90P01) | Contextual data. =1 if tract an urban area; =0 otherwise. |
| School Characteristics | |
| Bad School (A7,17,18A-F,19A-F,20A/C,22A/B) | Administrator-reported. Chronbach index of school characteristics: average class size; PTA membership % (reversed); dropout %; held-back %; student [below/above]-grade-level % (above reversed); academic track % (reversed); vocational track %. |
| Social Cohesion (S62B/E/I) | School-averaged student responses (on Likert scale) to: “I feel close to people at this school,” “I feel like I am part of this school,” and “I am happy to be at this school.” |
| %College Attendance (A21) | % of seniors attending 2- or 4-year college next year. |
| Size (ASIZE) | Administrator-reported. =1 if >1000 students; =0 otherwise. |
| Race Segregation (SEG1RCE5) | School-level difference in expected (under independence) and observed cross-race friendship ties, standardized by expected cross-race ties. |
| Parental Characteristics | |
| Education (PA12) | Parent-reported highest parental education. Five categories: <HS, HS/Equiv., Sm Coll., BA/Equiv., >College. |
| Unemployed/Welfare (PA21, PB17, PA16) | Parent-reported. =1 if either parent unemployed and seeking work or on welfare; =0 otherwise. |
| White Collar† (S14, S20) | =1 if highest-ranked par. occ. white collar (professional, manager, technical worker, office worker, sales worker, or restaurant worker); =0 otherwise. |
| Health Status (PC49[A-F] _[2/3]) | Parent-reported. Sum of indicator variables for both parents: obesity, migraines, allergies, asthma, alcoholism, and diabetes. |
| Risky Behavior (PA60-63, H1IR23) | Parent- and Interviewer-reported. Sum of indicator variables measuring infrequent seat belt usage, bing drinking frequency, smoking in household, and drinking frequency. |
| Social Support & Parenting | |
| Pos. Relationship (PC34A,D) | Parent-reported. Sum of dichotomous parent-child relationship characteristics: each =1 if “you get along well with [him/her],” and “you feel you can really trust [him/her]”; =0 otherwise. |
| Neg. Relationship (PC34C,E) | Parent-reported. Similar to above, for “you just do not understand [the adolescent]” and “[he/she] interferes with your activities.” |
| Par. School Involve. (PC25,26,28) | Parent-reported. Sum of indicator variables for talking with child about grades and school work, activities at school, and volunteering at school in the past week. |
| Parental Control† (H1WP2-7) | Sum of six indicator variables: Do your parents let you make your own decisions about: people you hang around with; what you wear; how much TV you watch; programs you watch; when go to bed; what you eat. |
| Social Support† (H1PR1-8) | Chronbach index on 1 (“not at all”) to 5 (“very much”) scale. How much: adults, teachers, parents, and friends care; family understand R; want to leave home (reversed); family has fun together, family pays attention. |
NOTE: Many variable question wordings are not verbatim, but are abbreviated for space reasons. Full descriptions of all source variables are available in Add Health Wave 1 documentation. Variables are student-reported unless otherwise indicated.
†
Averaged from both twin reports to capture shared environmental characteristics.