Fertility (within and across cohorts)  What is available over time?  Longitudinal perspectives  Complimentary analytical inputs and outputs  How to approach using the data  Causes and Caveats  Men and women  Methodological comparative strengths

Focus: Male Fertility  What is available over time?  Longitudinal perspectives  Caveats/Constraints  Methodological comparative strengths

The Fertility Questions :  Variations in wording and depth across cohorts.  More recent data is more comprehensive!  When possible use “created variables”– save yourself lots of work!  For the 1979 cohort – created longitudinal fertility and relationship rosters linking individuals over time for men and women  For the 1997 cohort—more depth: for the Young Adults, more history  cohorts compliment each other.

Selected Unique Features (e.g cohort and children)  Interviewed – again and again and again and again…and again  Siblings (and cousins!)  Enhancement through pooling (but with care!)  Cross-Generational possibilities  Large minority samples (Black & Hispanic 79 & 97)  Linking actual and expectations  For YA – increasing representation over time!

1979 Male Cohort 1) a) Some early gaps because cohort is at beginning (born ) b) Live birth history from 1979 on c) Data cleanup suggests that quality is “reasonable” – more for numbers born than dates of birth. d) Can be linked closely with full range of family employment, other related transitions, and activities. e) As of 2004, youngest respondent is now almost 40, and virtually all of their lifetime fertility up to that point is within survey years! f) Large sample, including Hispanic and African-American oversamples! g) Created variables 2) Cohort bound! 3) Siblings

1979 Young-Adult Male Cohort 1)Encompasses all of the male children of the 1979 female respondents who had have attained age 15. 2) Since 1994, we have interviewed biennially. Complete birth records related information such as family planning, wantedness, age at first intercourse, relationship information, etc. 3) Created variables for cumulative fertility. 4) Full range of complementary events. 5) Sample grows, and becomes more representative, with every survey round!

1979 Young-Adult Male Cohort (continued) 6) Originally more “selected out” as children of younger mothers; now increasing representative. 7) Also cohort bound—their mothers born between 1958 and ) Currently collected information for: (a)young adult lifetime (b) mothers since 1979 when they were (born )

Mom age at birth by YA age in survey year 1994 to 2002 Survey year mom age range at birthya age range 1994<20< <22< <19<21* 2000<26< <28< <30< <32<33 * data collection truncated

in NLSY79 Two Selected YA/Child Birth Cohorts

Male half of 1997 cohort 1)Currently useful for adolescent fertility research: in 2004 cohort was 19 to 23. 2) cohort bound without replacement (this is true for all cohorts) 3) comprehensive fertility/relationship history for survey years; more comprehensive than other cohorts. 4) Methodologically strong, with more detailed event history.

Quality of Male Fertility 1)Intense male intergenerational evaluation (report available) 2)“Confident” about 92% of reported births 3)Misresponse can be intentional (relating to relationship history) or unintentional (e.g. male not present) 4)Most reports at younger ages, less educated, for those with larger families 5)For event history research, misdating is bigger problem

Table 1. Distribution of Confidence Level for Selected Relationship Patterns, 1979 to 1998 (Unweighted, NLSY79) Paternity Likely ( Code 1 or 2) Paternity Unclear (Code 3) Paternity Not Likely (Code 4 or 5) N Dad present at birth ( ) Child always present Child has one entry or one exit Child has multiple entries and exits Child never present in home Child has one entry and one exit Dad not present at birth Child appears belatedly on fertility roster

Following Youth Through Later Adolescence/Early Adulthood Young Women14-17 (1968)  (1978)10 years NLSY79 (M&F)14-17 (1979)  (1989)10 years NLSY-YA (M&F)14-17 (1994 onward)  (2004)10 years NLSY97 (M&F)14-17 (1997)  (2004)7 years

For women

Table 4. Comparing Cumulative Survey Point and Event History Statistics (NLSY97) % ever married by age % ever cohabited by age % ever mar or cohab by age Event History Report Survey Point Cumulation Event History Report Survey Point Cumulation Event History Report Survey Point Cumulation 18 and over (total)

Note: Includes selected variables drawn from multivariate analysis Reference groups= college attendance

Table 5. Fertility Summary for NLSY Men Age in 1979 (and in 1998) (NLSY79 weighted estimates) % Ever Father % with 2+ Children Mean No. of Children Total White African American Hispanic

 With 1979, Longer term employment, relationships/family/income can be followed through 2004!