{smcl}
{* *! version 12 APR2020}{...}
{cmd:help pisaqreg} {right:also see: {help pisareg} {help pisastats} {help pisacmd} {help pisaoaxaca} {help pv} {help repest} }
{hline}
{title:Title}
{p2colset 5 17 20 2}{...}
{p2col :{hi: pisaqreg} {hline 2}} Quantile regression with PISA data and plausible values{p_end}
{p2colreset}{...}
{title:Syntax}
{p 8 18 2}
{cmd:pisaqreg}
{depvar} [{indepvars}] {ifin}
[{cmd:,} {it:options}]
{synoptset 24 tabbed}{...}
{synopthdr}
{synoptline}
{syntab:Main options}
{synopt :{opt cnt(string)}} Specifies a list of countries for which results will be calculated.
If OECD is specified, then results are provided for all OECD countries participating in this cycle.
Similarly, specifying PARTNERS will produce results for all partner countries and economies participating in this cycle.
Specifying PISA will produce similar results for all countries participating in this cycle.
If ALL is specified, then results are provided for all countries currently in your dataset.
Results can be provided for distinct groups of countries by specifying a list with three letter ISO codes.
For example, option cnt("AUS DEU POL") will produce results for Australia, Germany and Poland.
The OECD average is calculated only when OECD or PISA is specified.
Otherwise simple average is calculated.
If you don't specify this option, the results will be produced for all values of the variable cnt.
This variable must exist in the dataset.
{p_end}
{synopt :{help prefix_saving_option:{bf:{ul:save}(}{it:filename}{bf:, ...)}}}save
results to {it:filename}. You have to specify this option {p_end}
{syntab: Optional}
{synopt :{opt q(int)}} Estimates # quantile; default is q(0.5) which corresponds to the median {p_end}
{synopt :{opt over(var)}} Specifies a categorical variable for which you want to obtain statistics by each category.
The variable must be numerical with a sequence of integers denoting each category. {p_end}
{synopt :{opt round(int)}} Specifies how many decimal places you want to see in results tables. Default is 2. {p_end}
{synopt :{opt cycle(int)}} Specifies which PISA cycle you analyze.
This affects the list of countries recognized as OECD, PISA or PARTNERS in option cnt()
as well as which names of plausible values will be recognized when given as dependent variable.
Default is 2018. {p_end}
{synopt :{opt fast}} Specifying this option dramatically speeds up calculations at the cost of not fully valid estimates of standard errors.
Statistic itself is calculated properly, however, standard errors are calcuated analytically.
These standard errors are usually overstimated comparing to the original BRR method. {p_end}
{synoptline}
{title:Description}
{pstd}
You can use {cmd:pisaqreg} to run quantile regression with PISA data.
First variable listed after {cmd:pisadeco} is the dependent variable.
You can use any plausible value as the dependent variable but just specify last letters after pv*.
Thus, for pv*read just type read.
For any dataset you can type read, math, scie in which case the regression will be run 5 times (or 10 times for 2015 and 2018 data) on plausible values in reading, mathematics or science, respectively.
For any dataset you can also use proflevel which will run regression 5 times (or 10 times for 2015 and 2018 data) on a dummy indicator (or any other variable) that is based on any plausible value. This way you can estimate models with proficiency level indicators.
You can also use any plausible value existing in PISA dataset.
For PISA 2000 you can type: math, scie, read, read1, read2, read3, math1, math2, proflevel.
For PISA 2003 you can type: math, scie, read, math1, math2, math3, math4, prob, proflevel.
For PISA 2006 you can type: math, scie, read, intr, supp, eps, isi, use, proflevel.
For PISA 2009 you can type: math, scie, read, era, read1, read2, read3, read4, read5, proflevel.
For PISA 2012 you can type: math, scie, read, macc, macq, macs, macu, mape, mapf, mapi, proflevel.
For PISA 2015 you can type: math, scie, read, scep, sced, scid, skco, skpe, ssph, ssli, sses, proflevel.
For PISA 2018 you can type: math, scie, read, glcm, rcli, rcun, rcer, rtsn, rtml, proflevel.
The final result will be calculated as a mean of these five (or 10 for 2015 and 2018 data) regressions.
You can also specify other variables as dependent variables.
In this case the command will perform a standard quantile regression with one dependent variable.
Standard errors are obtained by the BRR method unless fast option is specified.
With fast option standard errors are not correct but point estimates are.
The command uses survey information provided in the original publicly available PISA datasets.
You need to keep variables like cnt or w_fstuwt and w_fst* unless you specify your own weight prefix.
{cmd: pisaqreg} returns matrices with point estimates and standard errors, separately for each over() category.
Type return list after executing {cmd: pisaqreg} to see what is available.
{title:Examples}
{pstd}
{phang2}{cmd:. pisaqreg read escs, cnt(POL) save(example1)} {p_end}
{phang2}{cmd:. pisaqreg read escs gender, q(0.75) cnt(AUS) save(example2) round(5)} {p_end}
{phang2}{cmd:. pisaqreg math escs, q(0.2) over(gender) cnt(AUS POL GBR) save(example3)} {p_end}
{phang2}{cmd:. pisaqreg scie escs gender, q(0.1) fast cnt(OECD) cycle(2015) save(example4)} {p_end}
{title:References}
When using our package please provide this reference in your work:
{phang} Maciej Jakubowski & Artur Pokropek (2017), {it: PISATOOLS: Stata module to facilitate analysis of the data from the PISA OECD study}, Statistical Software Components, Boston College Department of Economics.{p_end}
The formulas were taken from:
{phang}OECD (2009), {it:PISA Data Analysis Manual: SPSS and SAS, Second Edition}, OECD, Paris{p_end}
{phang}OECD (2017), {it:PISA 2015 Technical Report}, OECD, Paris{p_end}
{phang}Rubin, D. B. (1987), {it:Multiple imputations for nonresponse in surveys}, New York, John Wiley and Sons{p_end}
{title:Authors}
{pstd}
{phang} Maciej Jakubowski, Evidence Institute and University of Warsaw, Poland
email: mj@evidenceinstitute.pl {p_end}
{phang} Artur Pokropek, Institute of Philosophy and Sociology, Polish Academy of Sciences {p_end}
{title:Also see}
{pstd}
Other commands in this package {help pisastats}, {help pisareg}, {help pisacmd}, {help pisaoaxaca}. {p_end}
{pstd} User-written commands pv.ado or repest.ado. Type {help pv} or {help repest} if installed. {p_end}
{title:Version}
{pstd} Last updated April 2020, by Maciej Jakubowski {p_end}