Understanding Society User Support

Carolin,

Your problem is not weights but how you are using longitudinal dataset. By default the longitudinal aspect means that the dataset does not represent immigrants since wave 1 (or since the boost). If you pick wave 5 you will have only immigrants who came to the country before wave 1 - it does not represent immigrants who came to the country in the previous 5 years. You need to carefully keep this in mind.
Your best option is to just select wave 6 and analyse it separately with ui_xw weights. It has a boost of immigrants and is representative of the country population (including all immigrants) at that point of time.
Pooling across waves needs to be done extremely carefully (or better avoided) because the definition of population of immigrants is different in each wave. If you are interested in studying only immigrants who immigrated to the country before 1991 you have no problems- you can pull all the datasets in the usual way.
Wave 1 with us_xw weights are also representative of the population, including immigrants at that time. Let me know if you want to pool the data - it won't be straightforward. But first think conceptually if you think immigrants at the time of wave 1 are similar to those at wave 6.

Hope this helps,
Olena

Dear Olena,

Thanks a lot for your help. I did read the relevant sections on immigrants in the help files but did not completely understand the implications as it seems. Your answer helped me to clarify this.

So, if we run cross-sectional regressions in wave 6 only, we'd use the us_xw weights, and then we could run panel regressions in waves 6-10 using longitudinal ui_ weights (those that refer to wave 10), is that correct?

Carolin

Carolin,

Use ui_xw weight for wave 6, and use ui_lw weight if your longitudinal analysis starts at wave 6 or later (remember you don't have new immigrants since wave 6 in your analysis).

Olena

Hi Olena,

Thanks for the quick reply. One last question (at the moment, at least): the sample is representative of immigrants in wave 6, but is it for the following waves too, when we look at it from a panel perspective?

Thanks,
Carolin

Carolin,

Yes, in a sense that all immigrants who were present in the country are represented longitudinally (some would have left the country and this is somewhat captured in the data). So at wave 10 you can study all immigrants who were in the country continuously for the last 4-5 years (since wave 6), and immigrated to GB at any time since wave 6 (check if IEMB covers NI).

Hope this helps,
Olena

That does help a lot. Thanks, Olena.

Carolin,

Here are replies to b) and c):
If you are analysing households, and you want to represent households in the population then use household weights (and one observation for each household);
If you want to represent reference people of households (whatever it may mean) or heads of households (this may be a different person to that who gave a household interview) use individual weights of that person (again, you may have only one observation per household).
If you want to represent individuals but to use household level variables in your model use individual level weights.

Someone else from the team will respond to question a).
Hope this helps,
Olena

Dear Alita,

Thanks, that helps a lot.

I have another follow-up question (probably fo Olena?). It may sound strange, but I can't find the longitudinal weights for our analysis of the period up to wave 10. If I'm not mistaken, we should use j_hhdenui_lw, given that we use waves 6-10 and want to represent households. I've gone through all files and found a number of cross-sectional weights, but for some reason I'm not able to locate the wave I need for my panel regressions.

Can you please tell me where to look or let me know if I'm supposed to use different weights?

Thanks,
Carolin

Carolin,

Thank you for your question. UKHLS does not think of households as longitudinal entities as they change with time. For this reason the design is set up to follow individuals longitudinally, and only individuals get longitudinal weights.
Theoretically it would be possible to define a weight for a longitudinal household if you have a definition for what this would mean in your situation. If you still decide to proceed with a longitudinal definition of a household and would like to specify it to me (with examples of what happens when a household splits, someone enters, someone is born, dies etc.) then I should be able to advice on the weights.

Hope this helps,
Olena

Dear Olena,

Thanks for the details. I'll meet my coauthors soon and will discuss the definition of households with them. For now, I think it would be the best if we continued with wave 6 only.

I have another question here: household wealth is collected in waves 4 and 8. We can't use wave-4 wealth because we want to exploit the IEMB sample. Could we use wave-8 wealth to proxy wave-6 wealth (I am aware that we'd have to make strong assumptions here)? What would happen to the weights? Is this even possible?

Thanks a lot,
Carolin

Carolin,

I can't comment on the substantive idea of using later wave income. I will only mention that I wouldn't use household income as it is at wave 8 to infer it for wave 6 - instead I would use individual income parts and reconstruct household income. This is because household income would change a lot for specific categories of people: e.g. those who married between wave 6 and 8 or got divorced.

In terms of weights as you would be using wave 6 and wave 8 information you should use wave 8 longitudinal weight and you'll be fine.

Hope this helps,
Olena

Hi Olena,

Thanks for the quick reply. We are looking at households and so, there are no longitudinal weights in this case. Is there something else we could do?

Carolin

Carolin,

If you tell me how you define your longitudinal households I would be able to suggest the best option for you. For example what happens if two people from a household split up?

Thanks,
Olena

Hi Olena,

Our research question doesn't depend on the wave number and we were wondering if we could just use wave 8. Earlier you recommended to use wave 6 to analyse immigrants but (perhaps another stupid question): is wave 8 as representative of (i) immigrants and (ii) the general population in that wave as wave 6? That would solve basically all our problems because then, we would have controls for wealth and debt, which are strongly correlated with housing outcomes.

Concerning your previous question: we look at immigrant households which we classify as "immigrant" if the household reference person (the person who pays the rent/mortgage) is an immigrant. If that immigrant HRP happens to divorce their spouse, we would drop the ex-spouse's new household (if it's even in the dataset) and treat the newly divorced immigrant as the same immigrant household as before. If the immigrant HRP marries or moves in with someone, we'd treat them as the HRP in the new household as well, even though the new partner may pay the rent.

Getting weights for this case would be brilliant as it would allow us to run a panel regression using waves 8 and 12 (that is, if using wave 8 makes sense in the first place).

Thanks so much,
Carolin

Carolin,

Wave 8 is representative of the population with one exception: it does not include immigrants that entered the country since wave 6.
Wave 6 includes all immigrants, including those who immigrated that year.
The way you describe your research question sounds like you can study individuals with some household attributes. So if you study household reference people with all the household and individual characteristics and you could potentially run this as an individual analysis with individual level weights.

Hope this helps,
Olena

Hi Olena,

Thanks, this helps a lot, again!

Yes, we are using information from the household head (age, age at migration, country of birth etc.) and the household (household income, hopefully household wealth, household size, region, marital status). If you think we can use individual weights and waves 8 and 12, this would be fantastic! Out of curiosity, is there a rule, or rule of thumb, to decide if individual weights can be used even though we treat the individual as an entire household? What if we used many more household-level variables than individual ones?

So, we would then likely only use wave 6 first (in order to retain the maximum number of immigrants) with wave-8 wealth and longitudinal w8 weights, and then we could use waves 8 and 12 (with a lower sample size) and longitudinal w12 weights.

Carolin

Carolin,

If you represent individuals and therefore run individual-level analysis you can use as many household attributes as you like (no limit). You will be describing individuals who are immigrants (for example) who live in such and such households. This is an individual-level analysis and would require individual-level weights.

Hope this helps,
Olena