Had intercourse		Irrespective of whether had intercourse:		If had intercourse and…
			Used hormonal		Did not use hormonal:		Used hormonal:
					Used coital (condoms or withdrawal)		Also used coital
	β	OR	β	OR	β	OR	β	OR
Desire for sex+	.22	1.25 ***	.18	1.20 ***	−.08	.92	−.13	.88 **
	(.02)		(.02)		(.06)		(.05)
Personal attitudes & intentions+
Approval: premarital sex	.03	1.03	.10	1.11 ***	.04	1.04	.07	1.07
	(.03)		(.03)		(.07)		(.07)
Approval: sex w. friends	.03	1.03	.07	1.07 **	−.24	.79 ***	−.05	.95
	(.02)		(.03)		(.07)		(.06)
Wants to get pregnant	.69	2.00 ***	−1.02	.36 ***	−2.23	.11 ***	−.49	.61
	(.10)		(.11)		(.17)		(.27)
Previous experiences+ & age
Sexual debut <=14 years†	.33	1.39	.43	1.54	−1.20	.30 *	−.55	.58
	(.27)		(.54)		(.52)		(.54)
Cum. no. sex partners	.13	1.14 ***	.08	1.09 ***	−.05	.95	−.02	.98
	(.01)		(.02)		(.03)		(.03)
Cumulative no. live births	−.74	.48 ***	.51	1.67 ***	.77	2.15 **	1.19	3.29 ***
	(.11)		(.13)		(.24)		(.31)
Age	−.24	.78 ***	−.31	.73 ***	−.30	.74 **	−.57	.57 ***
	(.03)		(.04)		(.10)		(.09)
Current relationship
Status (ref: none)
Married	3.44	31.22 ***	.64	1.90 ***	−2.33	.10 ***	−2.01	.13 ***
	(.15)		(.18)		(.42)		(.48)
Engaged	3.36	28.70 ***	.79	2.19 ***	−.87	.42 **	−1.42	.24 ***
	(.10)		(.11)		(.29)		(.32)
Special	3.05	21.19 ***	.34	1.40 ***	−.39	.68	−.90	.40 ***
	(.06)		(.06)		(.22)		(.21)
Relationship duration	.01	1.01 ***	−.00	1.00	−.02	.99 *	−.02	.98 ***
	(.00)		(.00)		(.01)		(.01)
Friend context+
Friends’ approval of sex	.21	1.23 ***	.11	1.12 ***	−.01	.99	.03	1.03
	(.02)		(.03)		(.06)		(.07)
Prop. friends sex. active	.15	1.16 ***	.29	1.33 ***	−.05	.95	−.30	.74 ***
	(.03)		(.03)		(.09)		(.08)
Family context+ & race
Parents’ approval of sex	.10	1.10 ***	.13	1.14 ***	−.24	.79 ***	−.05	.95
	(.02)		(.02)		(.06)		(.06)
Mother <20 at first birth†	.25	1.28	.10	1.10	.36	1.43	.03	1.03
	(.19)		(.38)		(.40)		(.41)
Mother’s education (ref: <H.S.) †
Completed H.S.	−.42	.66	.77	2.15	.58	1.78	.12	1.13
	(.34)		(.67)		(.67)		(.78)
Completed college	−.91	.40 *	1.27	3.56	1.25	3.51	.76	2.14
	(.37)		(.73)		(.77)		(.83)
Received public assistance as child†	.17	1.19	−.85	.43 *	−1.06	.35 **	−.10	.91
	(.20)		(.38)		(.41)		(.43)
African American†	.01	1.01	−.04	.96	.81	2.24	.37	1.45
	(.23)		(.43)		(.50)		(.52)
Institutional contexts+
School
Enrolled in college	−.00	1.00	.24	1.27 ***	−.01	.99	.25	1.28
	(.06)		(.07)		(.15)		(.16)
Religion
Highly religious†	−.01	.99	−.05	.95	−.85	.43 *	.16	1.17
	(.21)		(.41)		(.43)		(.43)
Freq. of religious attendance†	−.16	.85 *	−.36	.69 **	.07	1.07	.10	1.11
	(.06)		(.12)		(.13)		(.14)
Current contraceptive behavior
Used hormonal contra. this week	.74	2.09 ***	--		--		--
	(.12)		--		--		--
Desire for sex+ * Used hormonal	.06	1.06 *	--		--		--
	(.03)		--		--		--
Current sexual behavior
Had intercourse this week	--		.87	2.40 ***	--		--
	--		(.05)		--		--
Constant	−.80	.45	.76		11.43	***	12.99	***
	(.72)		(1.01)		(2.05)		(1.90)
Observations (weeks)	40,479		40,479		6,493		6,779
Number of respondents	518		518		357		310
Reference category	Did not have intercourse		Did not use hormonal		Did not use any method		Used hormonal but not coital

Note: For both panels, in the first model the sample is comprised of all of respondents’ study weeks. In the second model, the sample is comprised of respondents’ study weeks when they had intercourse and did not use hormonal contraception. In the third model, the sample is comprised of respondents’ study weeks when they had intercourse and used hormonal contraception. The number of respondents (and corresponding weeks) is not uniform across models because some respondents switched methods during the study. These respondents appear in multiple models.

Standard errors in parentheses,

^***p<0.001,

^**p<0.01,

^*p<0.05

⁺Measures are lagged and reflect respondents’ situation as of the prior week.

^†Measure was assessed once at baseline and therefore does not vary within respondents over time