. * nwsaom tutorial 10: endowment and creation, interactions, rate effects . * Requires the core nwcommands and the package nwsaom. . . nwwebuse glasgow, nwclear . . * A model to compare with . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity transties seed(4) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------ glasgow1_t~3 | Coefficient Std. err. z P>|z| [95% conf. interval] -------------+---------------------------------------------------------------- outdegree | -2.867764 .1349245 -21.25 0.000 -3.132211 -2.603317 reciprocity | 2.435639 .1836997 13.26 0.000 2.075595 2.795684 transties | 1.173796 .1325602 8.85 0.000 .9139823 1.433609 ------------------------------------------------------------------------------ Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 7.4252 5.5577 se | 1.4258 0.9936 Overall maximum convergence ratio: 0.082 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . . * --------------------------------------------------------------- . * Part 1: endowment and creation. Split an effect into a part that . * counts when a tie is created and a part that counts when a tie . * is given up. . * --------------------------------------------------------------- . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity endow(transties) creation(transtie > s) seed(6) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------- glasgow1_to_gla~3 | Coefficient Std. err. z P>|z| [95% conf. interval] ------------------+---------------------------------------------------------------- outdegree | -2.937801 .2219279 -13.24 0.000 -3.372771 -2.50283 reciprocity | 2.662705 .3052802 8.72 0.000 2.064367 3.261043 transtiesendow | -.3730114 .681025 -0.55 0.584 -1.707796 .961773 transtiescreation | 2.396332 .5770431 4.15 0.000 1.265348 3.527316 ----------------------------------------------------------------------------------- Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 6.3342 5.0200 se | 1.1150 0.8223 Overall maximum convergence ratio: 0.126 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . . * Reciprocity: are reciprocated ties harder to give up than they are attractive to make? . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree endow(reciprocity) creation(reciprocity) seed( > 6) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------- glasgow1_to_glasg~3 | Coefficient Std. err. z P>|z| [95% conf. interval] --------------------+---------------------------------------------------------------- outdegree | -2.184284 .1293756 -16.88 0.000 -2.437856 -1.930713 reciprocityendow | 1.159558 .5655688 2.05 0.040 .0510638 2.268053 reciprocitycreation | 4.080603 .4319001 9.45 0.000 3.234095 4.927112 ------------------------------------------------------------------------------------- Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 4.5166 3.7584 se | 0.6481 0.5292 Overall maximum convergence ratio: 0.125 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . . * A covariate effect split in the same way . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity transties endow(altx:alcohol1) cre > ation(altx:alcohol1) seed(4) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------- glasgow1_to_glasgow3 | Coefficient Std. err. z P>|z| [95% conf. interval] ----------------------+---------------------------------------------------------------- outdegree | -2.868272 .1250885 -22.93 0.000 -3.113441 -2.623103 reciprocity | 2.448188 .193526 12.65 0.000 2.068884 2.827492 altxendow_alcohol1 | -.3811653 .1916677 -1.99 0.047 -.7568271 -.0055035 altxcreation_alcohol1 | .2663148 .1141502 2.33 0.020 .0425845 .4900451 transties | 1.176264 .1279014 9.20 0.000 .9255822 1.426947 --------------------------------------------------------------------------------------- Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 7.5216 5.8361 se | 1.4005 1.1486 Overall maximum convergence ratio: 0.090 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . . * On a behavior . nwsaom, wave1(glasgow1) wave2(glasgow2) outdegree reciprocity behavior(alcohol1 alcohol2) linear q > uadraticendow quadraticcreation seed(4) ---------------------------------------------------------------------------------------------------- SAOM co-evolution (Method of Moments), waves: glasgow1 -> glasgow2 Actors: 50 Network rate: 5.530 (0.850) Behavior: alcohol1 alcohol2 Behavior rate: 1.242 (0.311) ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------- glasgow1_to_glasgow2 | Coefficient Std. err. z P>|z| [95% conf. interval] -----------------------+---------------------------------------------------------------- outdegree | -2.225501 .1288093 -17.28 0.000 -2.477962 -1.973039 reciprocity | 2.420582 .2492538 9.71 0.000 1.932053 2.90911 beh_linear | .424995 .3422905 1.24 0.214 -.2458821 1.095872 beh_quadratic_endow | .1106879 .4323379 0.26 0.798 -.7366789 .9580547 beh_quadratic_creation | -.217134 .4636833 -0.47 0.640 -1.125937 .6916686 ---------------------------------------------------------------------------------------- Overall maximum convergence ratio: 0.133 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . . * --------------------------------------------------------------- . * Part 2: interactions. Does the pull of reciprocity depend on how much . * the sender drinks? . * --------------------------------------------------------------- . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity transties egox(alcohol1) interact( > egox#reciprocity) seed(4) detail ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------- glasgow1_to_glasgow3 | Coefficient Std. err. z P>|z| [95% conf. interval] ------------------------------+---------------------------------------------------------------- outdegree | -2.890084 .1388058 -20.82 0.000 -3.162138 -2.61803 reciprocity | 2.468652 .182564 13.52 0.000 2.110833 2.82647 egox_alcohol1 | .0909282 .1032645 0.88 0.379 -.1114666 .2933229 transties | 1.171759 .1430727 8.19 0.000 .8913419 1.452177 interact_nodeocov_reciprocity | -.1488986 .2342888 -0.64 0.525 -.6080962 .3102991 ----------------------------------------------------------------------------------------------- Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 7.5984 5.6681 se | 1.4431 1.0199 (conditional: rate = mean time to reach the observed distance, se = its SD) RSiena effect names: egox_alcohol1 alcohol1 ego interact_nodeocov_reciprocity alcohol1 ego x reciprocity Covariates centred by their means, as RSiena's coCovar(centered = TRUE): alcohol1 2.880 Convergence t-ratios (criterion: every |t| below 0.1; the overall maximum ratio below 0.25 is a sepa > rate criterion): outdegree -0.060 reciprocity -0.032 egox_alcohol1 -0.091 transties -0.045 interact_nodeocov_recip~ -0.104 Overall maximum convergence ratio: 0.134 . . * Two covariate effects interacting: do pupils who drink prefer friends who smoke like themselves? . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity transties samex(smoke1) egox(alcoh > ol1) interact(samex#egox) seed(4) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------- glasgow1_to_glasgow3 | Coefficient Std. err. z P>|z| [95% conf. interval] ----------------------------+---------------------------------------------------------------- outdegree | -3.220108 .2206385 -14.59 0.000 -3.652551 -2.787664 reciprocity | 2.469673 .1932599 12.78 0.000 2.09089 2.848455 samex_smoke1 | .3569517 .1852166 1.93 0.054 -.0060662 .7199696 egox_alcohol1 | .3827144 .1439699 2.66 0.008 .1005385 .6648903 transties | 1.148795 .123673 9.29 0.000 .9064005 1.39119 interact_nodematch_nodeocov | -.4448597 .1660293 -2.68 0.007 -.7702712 -.1194483 --------------------------------------------------------------------------------------------- Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 7.5054 5.6764 se | 1.4264 1.0365 Overall maximum convergence ratio: 0.081 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . . * --------------------------------------------------------------- . * Part 3: the rate. By default all pupils have the same rate. . * --------------------------------------------------------------- . * Do heavier drinkers change their friendships more often? . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity transties ratecov(alcohol1) seed(4 > ) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------ glasgow1_t~3 | Coefficient Std. err. z P>|z| [95% conf. interval] -------------+---------------------------------------------------------------- outdegree | -2.871685 .1312082 -21.89 0.000 -3.128849 -2.614522 reciprocity | 2.428765 .1855593 13.09 0.000 2.065076 2.792455 transties | 1.180279 .1278749 9.23 0.000 .9296485 1.430909 ------------------------------------------------------------------------------ Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 7.1977 5.7059 se | 1.4212 1.0823 Covariate-rate coefficient (alcohol1): 0.4191 (se 0.1443) Overall maximum convergence ratio: 0.150 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met . matrix list e(ratecoefs) symmetric e(ratecoefs)[1,1] alcohol1 r1 .41912671 . . * Does the rate depend on how many friends a pupil has? . nwsaom, waves(glasgow1 glasgow2 glasgow3) outdegree reciprocity transties outrate seed(4) ---------------------------------------------------------------------------------------------------- SAOM (Method of Moments, conditional), waves: glasgow1 glasgow2 glasgow3 Actors: 50 Periods: 2 ---------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------ glasgow1_t~3 | Coefficient Std. err. z P>|z| [95% conf. interval] -------------+---------------------------------------------------------------- outdegree | -2.700628 .1371836 -19.69 0.000 -2.969503 -2.431753 reciprocity | 2.357928 .2132406 11.06 0.000 1.939984 2.775872 transties | 1.128274 .1423971 7.92 0.000 .8491806 1.407367 ------------------------------------------------------------------------------ Rate parameters (estimated, one per inter-wave period): | period1 period2 -------------+--------------------- rate | 3.9495 2.9879 se | 0.8066 0.5726 Covariate-rate coefficient (outrate): 0.2462 (se 0.2564) Overall maximum convergence ratio: 0.103 (criterion: below 0.25; met) Convergence t-ratios (criterion: all below 0.1 in absolute value): met .