Hello,

I would like to see if the regression coefficients are statistically different for a low income group vs a high income group, when looking at the reaction to different levels of cost sharing (insurance plans)

the ran_plan_groups are dummies for which insurance plan the participants belong to. pct50_income_person is a dummy as well assigning participants to the two income groups.

Is this the rigtig way to approach it? sureg was mentioned somewhere as well.


Code:
set seed 620549
local controls age baseline_fam_size good_health bad_health


quietly regress log_spending rand_plan_group2 rand_plan_group3 rand_plan_group4 rand_plan_group5 rand_plan_group6  `controls' demeaned_fam_start_month_site* demeaned_cal_year* if pct50_income_person ==0 
est sto model_low_income

quietly regress log_spending rand_plan_group2 rand_plan_group3 rand_plan_group4 rand_plan_group5 rand_plan_group6  `controls' demeaned_fam_start_month_site* demeaned_cal_year* if pct50_income_person ==1
est sto model_high_income

suest model_low_income model_high_income, cluster(ifamily)


I get the following results but im not sure how to interpret it.

Code:
                                                Number of obs     =     17,810

                                    (Std. Err. adjusted for 2,973 clusters in ifamily)
--------------------------------------------------------------------------------------
                     |               Robust
                     |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
---------------------+----------------------------------------------------------------
model_low_income_m~n |
    rand_plan_group2 |  -.8133025   .1192149    -6.82   0.000    -1.046959   -.5796456
    rand_plan_group3 |  -.6605734   .1177767    -5.61   0.000    -.8914115   -.4297352
    rand_plan_group4 |  -1.030376   .1515841    -6.80   0.000    -1.327476   -.7332768
    rand_plan_group5 |  -1.441263   .1193879   -12.07   0.000    -1.675259   -1.207267
    rand_plan_group6 |  -1.087224   .0926923   -11.73   0.000    -1.268898   -.9055505
---------------------+----------------------------------------------------------------
model_low_income_l~r |
               _cons |   1.588036   .0199406    79.64   0.000     1.548953    1.627118
---------------------+----------------------------------------------------------------


Code:
model_high_income_~n |
    rand_plan_group2 |   -.400343   .1259898    -3.18   0.001    -.6472784   -.1534076
    rand_plan_group3 |  -.2398797   .1964297    -1.22   0.222    -.6248748    .1451154
    rand_plan_group4 |  -.7494231   .1771273    -4.23   0.000    -1.096586     -.40226
    rand_plan_group5 |  -1.089795   .1532231    -7.11   0.000    -1.390107   -.7894836
    rand_plan_group6 |  -.6580158   .1334854    -4.93   0.000    -.9196423   -.3963892
---------------------+----------------------------------------------------------------
model_high_income_~r |
               _cons |   1.078982   .0489945    22.02   0.000     .9829543    1.175009
--------------------------------------------------------------------------------------






Thank you !