Understanding Society User Support

Henrique,

Thank you for your question. Just to clarify:
1) do you use wave 7-11 of the mainstage in one model?
2) You mention "Our treatment variable takes value 1 for Covid waves and 0 otherwise". Is it 1 if a person present in a Covid wave? Can you clarify please what you mean by this?

Thank you,
Olena

Thanks for your reply, and my apologies for not being clear. Responding to your questions:

1) We have combined the mainstage and Covid waves in a long format. We have a single model where we compare data from waves 7-11 of the mainstage and waves 1-9 of the Covid-19 Survey (we do not estimate separate models for the mainstage and Covid waves).

2) Our model includes a time dummy (our treatment variable) that takes value 1 for all observations in the Covid waves and 0 for all observations in the mainstage waves. For example: If a person is present in wave 9 of the mainstage and wave 1 of the Covid survey, he/she would have a value of 0 in our time dummy in wave 9 of the mainstage and a value of 1 in wave 1 of the Covid survey.

Let me know if this is clear.

Kind regards,
Henrique

Henrique,

Just to clarify, by treatment variable do you mean that you are interested in 0/1 effect of your treatment variable? Do you study nonresponse: so an effect of response to the mainstage and nonresponse to Covid survey? Or maybe you are looking into measurement error - a difference in response to the mainstage vs. Covid survey?

If not, could you clarify please as weights will depend on that?
Best,
Olena

Thanks for your reply.

We are indeed interested in a 0/1 effect of our treatment variable. We are simply regressing a mental health variable on this binary (0–1) variable, and the coefficient is interpreted as the average causal effect of Covid-19 on mental health.

I am not sure I understood your question, but it seems that we are not studying non-response and measurement errors.

We are not studying the effect of response to the mainstage and nonresponse to the Covid survey. We are pooling observations across the mainstage and Covid waves and comparing outcomes before and during the pandemic. We don't consider changes in mental health from the mainstage to the Covid survey as measurement errors.

Let me know which further information I should provide.

Kind regards,
Henrique

Henrique,

Thank you. This clarifies it. Can you tell me how you are using Covid data - do you need a person to participate in all of the waves?

Thank you,
Olena

No, a person just needs to participate in one of the Covid waves.

Kind regards,
Henrique

Ok, then your best option would be to use wave 11 longitudinal weight as your base weight, and predict response in your model.

Hope this helps,
Olena

Thanks so much for your suggestion. So what you are suggesting would be to fit a conditional model of response, where the dependent variable would be a 0/1 indicator of whether a participant responded to every Covid wave (from 1 to 9)?

Thank you,
Henrique

Henrique,

Do you mean you want to model first nonresponse to a Covid wave, and then conditional on response your model of interest? It is a possibility, as long as you understand what you are doing, and what you want to represent.

Hope this helps,
Olena

Sorry, I am a bit confused. My wave-combination of interest is participants at waves 7 to 11 of the mainstage and 1 to 9 of the Covid survey. You suggested I use wave 11 longitudinal weight as the base weight and predict response in my model. But I am not sure how to fit a conditional model (logit) of response to my wave-combination of interest. Should I model nonresponse to both mainstage and Covid waves?

Thank you,
Henrique

Henrique,

Thank you. This clarifies the question. You should put the model together. If a person is in your model code response=1, if not, code response=0. If you have different models with different sets of people you may need different weights for each.

Hope this helps,
Olena

Sorry for the late reply. Thanks so much for your suggestion, I've worked through it this week! I would just like to clarify two questions to make sure this is the optimal weight strategy for our study:

(1) Using wave 11 longitudinal weight as base weight imposes a relevant restriction to our sample: an individual must have participated in all waves from 1 to 11 of the mainstage to have non-zero longitudinal weight. This departs from our original sample of interest: participants in the COVID-19 survey who had responded to at least one wave of the mainstage from 7 to 11 ( so not all from 1 to 11). I am just wondering if there is an alternative base weight closer better suited for our sample.

(2) If in our analysis we pool all observations from waves 7 to 11 of the mainstage and waves 1 to 9 of the COVID-19 survey (treating waves as repeated cross-sections instead of carrying longitudinal analysis) can we use cross-sectional weights?

Thanks so much again!

Kind regards,
Henrique

Henrique,

Thank you for your questions.

1) You could start at wave 7 longitudinal weight. The gain will be small, but you will have to take mortality into account.
2) In this situation you could just use cross-sectional weights provided with Covid data.

Hope this helps,
Olena

Thanks for all your help!