Announcement

Collapse
No announcement yet.
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Use of higher-level variables (i.e., variables not measured at the individual level) as IVs in individual level survey data: any problem?

    Hi all. I have a methodological question concerning the use of instrumental variables. I'm working on a paper that uses individual-level survey data. To that data, I added variables from the municipalities where individuals in the survey data live. They include geographical variables, which are: altitude, longitude, distance to the state’s capital, and anthropic use of soil.

    The instrumented variables are: number of media outlets in a municipality per 100k people (ln_veiculos_por_100k_hab), whether a municipality has a tv station or radio station (tvcom_radio_am_fm), and the interaction between the two variables (veiculos_100k_x_tvcom_radio).

    The dependent variable is whether the survey respondent turned out to vote in the last general election (turnout_first_round).

    I want to use these geographical variables as instruments in my regression.

    I ran a IV-probit model using the aforementioned geographical variables as instruments (see model’s output below).

    The question is: Is there any objection to the use of "higher-level" variables (i.e., variables not measured at the individual level) as instrumental variables in models with individual-level data?

    Thank you


    Code:
    . ivprobit turnout_first_round pol_interest intensity_follow_media retrosp_eval_socio party_id unemployed sexo educ ec_casado beneficiary_bf rel_evang rel_cat color_nowhite (ln_veiculos_por_100k_hab tvcom_radio_am_fm veiculos_100k_x_tvcom_radio = altitude dist_cap_est longitude area_hec_anthropic_perc), twostep
    Checking reduced-form model...
    
    Two-step probit with endogenous regressors        Number of obs   =      2,243
                                                      Wald chi2(15)   =      40.84
                                                      Prob > chi2     =     0.0003
    
    ---------------------------------------------------------------------------------------------
                                |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
    ----------------------------+----------------------------------------------------------------
       ln_veiculos_por_100k_hab |   4.757881   1.610617     2.95   0.003     1.601129    7.914633
              tvcom_radio_am_fm |   5.142635   1.553713     3.31   0.001     2.097415    8.187856
    veiculos_100k_x_tvcom_radio |  -6.554101   2.044757    -3.21   0.001    -10.56175   -2.546451
                   pol_interest |   .3006396   .0847307     3.55   0.000     .1345704    .4667087
         intensity_follow_media |  -.1738803   .0868592    -2.00   0.045    -.3441211   -.0036394
             retrosp_eval_socio |  -.0281594   .0512776    -0.55   0.583    -.1286617     .072343
                       party_id |   .3859058   .1455576     2.65   0.008      .100618    .6711935
                     unemployed |  -.3206427   .1794491    -1.79   0.074    -.6723564    .0310711
                           sexo |   .1277034   .1189566     1.07   0.283    -.1054472     .360854
                           educ |   .0572311   .0306147     1.87   0.062    -.0027725    .1172348
                      ec_casado |   .1395974   .1284862     1.09   0.277     -.112231    .3914258
                 beneficiary_bf |   .0892701   .1381738     0.65   0.518    -.1815455    .3600858
                      rel_evang |  -.1692903   .1862543    -0.91   0.363    -.5343419    .1957614
                        rel_cat |   .1692262   .1701128     0.99   0.320    -.1641889    .5026412
                  color_nowhite |  -.0886158     .13524    -0.66   0.512    -.3536814    .1764498
                          _cons |  -1.968669   .8197188    -2.40   0.016    -3.575288   -.3620493
    ---------------------------------------------------------------------------------------------
    Instrumented:  ln_veiculos_por_100k_hab tvcom_radio_am_fm veiculos_100k_x_tvcom_radio
    Instruments:   pol_interest intensity_follow_media retrosp_eval_socio party_id unemployed
                   sexo educ ec_casado beneficiary_bf rel_evang rel_cat color_nowhite altitude
                   dist_cap_est longitude area_hec_anthropic_perc
    ---------------------------------------------------------------------------------------------
    Wald test of exogeneity: chi2(3) = 41.46                  Prob > chi2 = 0.0000
    
    . overid
    
    Test of overidentifying restrictions:
    Amemiya-Lee-Newey minimum chi-sq statistic    1.071  Chi-sq(1)   P-value = 0.3008
Working...
X