2024 Stata aweight

weight 74 3019.459 777.1936 1760 4840 The display is accurate but is not as aesthetically pleasing as we may wish, particularly if we plan to use the output directly in published work. By placing formats on the variables, we can control how the table appears:. format price weight %9.2fc. summarize price weight, format Variable Obs Mean Std. dev .... Perris ellis

关于我们. 1. 简介. 1.1 为何要使用 weight. 在数据分析中有时需要为观测值设置不同的权重，例如以下情形：. 在抽样过程中，不同子总体里的个体被抽中的概率不同，那么不同样本个体代表的总体数量也不同，需要以权重进行反映。. 例如，在分层抽样中，按男性 ...weight, options where square brackets distinguish optional qualiﬁers and options from required ones. In this diagram, varlist denotes a list of variable names, command denotes a Stata command, exp denotes an algebraic expression, range denotes an observation range, weight denotes a weighting expression, and options denotes a list of options. 1Hello, I wanted to do a t-test using variables age and doctor-diagnosed asthma (ConDr) accounting also for my sample weight which is int121314. I tried thePearson Correlation: Used to measure the correlation between two continuous variables. (e.g. height and weight) Spearman Correlation: Used to measure the correlation between two ranked variables. (e.g. rank of a student’s math exam score vs. rank of their science exam score in a class) Kendall’s Correlation: Used when you wish to use ...Let me explain: Stata provides four kinds of weights which are best described in terms of their intended use: fweights, or frequency weights, or duplication weights. Specify these and Stata is supposed to produce the same answers as if you replace each observation j with w_j copies of itself. These are useful when the data is stored in a ...Stata understands four types of weighting: aweight Analytical weights, used in weighted least squares (WLS) regression and similar procedures. fweight Frequency weights, counting the number of duplicated observations. Frequency weights must be integers. iweight Importance weights, however you define importance. pweight Probability or sampling weights, proportional to the inverse of the ...The source of the difference is described in the Stata manual. Briefly put, Stata is estimating \sigma^{2}/W, where W denotes the average value of the weights. Stata reports the sum of the weights, so that the estimated value for \sigma^{2} can be obtained by the calculation (118.12) x [(2.3230e-01) / 10] = 2.744RE: st: proper use of aweight. Date. Fri, 20 Apr 2012 16:22:12 +0000. Thank you for the help and apologize for incorrectly using "posted code". I was referring to the supplemental .do files available online for several (non-STATA) journal articles. After reading the STATA reference manual [U] 20.18, it seemed aweight should only be used with ...Stata understands four types of weighting: aweight Analytical weights, used in weighted least squares (WLS) regression and similar procedures. fweight Frequency weights, counting the number of duplicated observations. Frequency weights must be integers. iweight Importance weights, however you define importance. pweight Probability or sampling weights, proportional to the inverse of the ...You are asked to post on Statalist using your full real name, including given name(s) and a family name, such as "Ronald Fisher" or "Gertrude M. Cox". Giving full names is one of the ways in which we show respect for others and is a long tradition on Statalist. It is also much easier to get to know people when real names are used.Survey Weights: A Step-by-Step Guide to Calculation, by Richard Valliant and Jill Dever, walks readers through the whys and hows of creating and adjusting …Title stata.com graph twoway lﬁt ... Weights, if speciﬁed, affect estimation but not how the weighted results are plotted. See [U] 11.1.6 weight. Menu Graphics > Twoway graph (scatter, line, etc.) Description twoway lfit calculates the prediction for yvar from a linear regression of yvar on xvar and plots the resulting line. Optionsexamples from epidemiology, and Stata datasets and do-ﬁles used in the text are available.Cameron and Trivedi(2010) discuss linear regression using econometric examples with Stata.Mitchell(2012) ... weight -.0065879 .0006371 -10.34 0.000 -.0078583 -.0053175 foreign -1.650029 1.075994 -1.53 0.130 -3.7955 .4954422 _cons 41.6797 2.165547 19.25 …st: RE: Using weights with tabulate command. Date. Thu, 18 Mar 2004 16:11:10 -0000. With -tabulate-, weights are assumed to be frequency weights unless otherwise indicated. Your weights sound like analytic weights. . by country: tab illness [aw=weight01] With -summarize- weights are assumed to be analytic weights unless otherwise indicated.Stata has four different options for weighting statistical analyses. You can read more about these options by typing help weight into the command line in Stata. However, only two …Oct 6, 2017 · 3. Each record represents observation of an aggregate of entities (people perhaps) rather than a single entity, and the variables recorded represent aggregate-wide averages of the measured values for those entities. The weight is set to the number of entities in the aggregate. If it's this, you have aweights. 1 like. 1-3. 2-5. Syracuse. 0-3. 4-3. Expert recap and game analysis of the Virginia Cavaliers vs. North Carolina Tar Heels NCAAF game from October 21, 2023 on ESPN.Stata offers 4 weighting options: frequency weights (fweight), analytic weights (aweight), probability weights (pweight) and importance weights (iweight). This document aims at laying out precisely how Stata obtains coefficients and standard er- rors when you use one of these options, and what kind of weighting to use, depending on the problem 1.3. Using Replicate Weights with Built-In SAS Procedures SAS/STAT software provides a set of procedures whose names begin with SURVEY that are the counterparts of BASE SAS procedures. This document concentrates on the basic information needed to make use of replicate weights. SAS procedures have many options and capabilities not discussed in …The source of the difference is described in the Stata manual. Briefly put, Stata is estimating \sigma^{2}/W, where W denotes the average value of the weights. Stata reports the sum of the weights, so that the estimated value for \sigma^{2} can be obtained by the calculation (118.12) x [(2.3230e-01) / 10] = 2.744Apr 29, 2015 ... But let's ignore the iweight for programmers, and focus on the other three: fweight or frequency weight - is probably the easiest, but most ...IPW estimators use estimated probability weights to correct for missing data on the potential outcomes. teffects ipw accepts a continuous, binary, count, fractional, or nonnegative outcome and allows a multivalued treatment. See[TE] teffects intro or[TE] teffects intro advanced for more information about estimating treatment effects from ...Jan 12, 2018 · 1 Answer. Sorted by: 2. First you should determine whether the weights of x are sampling weights, frequency weights or analytic weights. Then, if y is your dependent variable and x_weights is the variable that contains the weights for your independent variable, type in: mean y [pweight = x_weight] for sampling (probability) weights. Hi Statalist, Where can I find the computation detail of analytical weights (aweight) ? In User guide 20.22.2, it says : If you specify aweights, they are: 1. Normalized to sum to N and then 2. Insert in the ... as fweights. What does it mean (in formula) to normalize the weight to sum to N? Where can I find the formula for the normalization.Example: Quantile Regression in Stata. For this example we will use the built-in Stata dataset called auto. First we’ll fit a linear regression model using weight as a predictor variable and mpg as a response variable. This will tell us the expected average mpg of a car, based on its weight. Then we’ll fit a quantile regression model to ...Mar 9, 2016 ... resid_dev without freq_weights produces the same deviance residuals as Stata, i.e. it is unweighted. Using aweights in Stata produces exactly ...In a simple situation, the values of group could be, for example, consecutive integers. Here a loop controlled by forvalues is easiest. Below is the whole structure, which we will explain step by step. . quietly forvalues i = 1/50 { . summarize response [w=weight] if group == `i', detail . replace wtmedian = r (p50) if group == `i' .Stata can use aweights or pweights. There are a number of sites on the web that recommend using working weights (wwt) in SPSS to approximate results that would be obtained using pweights. Working weights are analytic weights divided by the mean weight. Supposedly, working weights provide better estimates of standard errors than using plain ...examples from epidemiology, and Stata datasets and do-ﬁles used in the text are available.Cameron and Trivedi(2010) discuss linear regression using econometric examples with Stata.Mitchell(2012) ... weight -.0065879 .0006371 -10.34 0.000 -.0078583 -.0053175 foreign -1.650029 1.075994 -1.53 0.130 -3.7955 .4954422 _cons 41.6797 2.165547 19.25 …By definition, a probability weight is the inverse of the probability of being included in the sample due to the sampling design (except for a certainty PSU, see below). The probability weight, called a pweight in Stata, is calculated as N/n, where N = the number of elements in the population and n = the number of elements in the sample. For ... Analytic weight in Stata •AWEIGHT –Inversely proportional to the variance of an observation –Variance of the jthobservation is assumed to be σ2/w j, where w jare the weights –For most Stata commands, the recorded scale of aweightsis irrelevant –Stata internally rescales frequencies, so sum of weights equals sample size tab x [aweight ... st: RE: Using weights with tabulate command. Date. Thu, 18 Mar 2004 16:11:10 -0000. With -tabulate-, weights are assumed to be frequency weights unless otherwise indicated. Your weights sound like analytic weights. . by country: tab illness [aw=weight01] With -summarize- weights are assumed to be analytic weights unless otherwise indicated.Sep 7, 2015 ... After running psmatch2 in Stata, the program creates a variable called _weight. This indicates which observations are used in matching, and what ...What is the effect of specifying aweights with regress? Clarification on analytic weights with linear regression A popular request on the help line is to describe the effect of specifying [aweight=exp] with regress in terms of transformation of the dependent and independent variables. The mechanical answer is that typingMay 23, 2017 · Aweight vs. fweight vs. pweight. 23 May 2017, 20:45. Dear All, I am trying to estimate a treatment effect using an aggregated difference-in-difference linear regression. I have collapsed the panel from an individual level panel to treated and control (2 groups only) groups. Can I use "xtivreg2,fe" even >> though I don't have any endogenous variables? In other words, can >> "xtivreg2 [aweight=],fe" be an alternative to a simple fixed effect >> model with a weight? If I can't use xtivreg2, are there any other ways >> I can run a fixed effect model with an analytic weight?Anyway, assuming it is aweights, you can do this: Code: mean age [aweight = npatients], over (code) test A = B. where npatients is the name of the variable containing the number of patients in each study, and A and B are the value labels attached to your variable code. In the future, when asking for help with code, include example data in your ...Weights collapse allows all four weight types; the default is aweights. Weight normalization affects only the sum, count, sd, semean, and sebinomial statistics. Let j index observations and i index by-groups. Here are the deﬁnitions for count and sum with weights: count: unweighted: N i, the number of observations in group i aweight: NCorrection to my prior message: I did: Step 1. mean age1 age2 [aweight = wt] Step 2 lincom (age1)-(age2) to get the t-test and probabilities Pls let me know what you think thanks, Sripal. weight(varname) is an optional option. Therefore, without this option, asgen works like egen command and finds simple mean. Example 1: Weighted average mean for kstock using the variable mvalue as a weight. Code: webuse grunfeld asgen WM_kstock = kstock, w (mvalue) Example 2: Weighted average mean using an expression.summarize with aweights displays s for the "Std. Dev.", where s is calculated according to the formula: s 2 = (1/(n - 1)) sum w* i (x i - xbar) 2 where x i ( i = 1 , 2 , ..., n ) are the data, w* i are "normalized" weights, and xbar is the weighted mean.6) that "Weight normalization affects only the sum, count, sd, semean, and sebinomial statistics.". On p.7 in the manual, in example 4, an example of a weighted mean in a similar setting that I use, is shown, as following: . collapse (mean) age income (median) medage=age medinc=income (rawsum) pop > [aweight=pop], by (region) Is it possible to ... IPW estimators use estimated probability weights to correct for missing data on the potential outcomes. teffects ipw accepts a continuous, binary, count, fractional, or nonnegative outcome and allows a multivalued treatment. See[TE] teffects intro or[TE] teffects intro advanced for more information about estimating treatment effects from ...aweights and fweights are allowed; see [U] 11.1.6 weight. Menu Statistics > Summaries, tables, and tests > Other tables > Table of means, std. dev., and frequencies Description tabulate, summarize() produces one- and two-way tables (breakdowns) of means and standard deviations. See[R] tabulate oneway and[R] tabulate twoway for one- and two-way ... Tabulate With Weights In Stata. 28 Oct 2020, 19:56. I have a variable "education" which is 3-level and ordinal and I have a binary variable "urban" which equals to '1' if the individual is in urban area or '0' if they are not. I also have sample weights in a variable "sampleWeights" to scale my data up to a full county level-these weight values ...Mar 23, 2017 · Stata's -fweight-s are used to replicate an observation a given number of times. So, if you had, say 10 observations in your data set with all of the same values on the regression variables, you could replace that with a single observation and use an -fweight- of 10 instead. But that is not what you have at all. RE: st: RE: aweight option in kdensity. From: "vora n" <[email protected]> References: st: aweight option in kdensity. From: "vora n" <[email protected]> Prev by Date: Re: st: 3D raphic in stata; Next by Date: st: How can I correct ivreg2 coefficients for AR1? Previous by thread: st: aweight option in kdensity6) that "Weight normalization affects only the sum, count, sd, semean, and sebinomial statistics.". On p.7 in the manual, in example 4, an example of a weighted mean in a similar setting that I use, is shown, as following: . collapse (mean) age income (median) medage=age medinc=income (rawsum) pop > [aweight=pop], by (region) Is it possible to ...covariates because of the study design. In contrast, covariates must be balanced by weighting or matching in observational data because treatment assignment is related to the covariates that also affect the outcome of interest. The estimators implemented in teffects and stteffects use a model or matching method toDescription. reghdfe is a generalization of areg (and xtreg,fe, xtivreg,fe) for multiple levels of fixed effects, and multi-way clustering.. For alternative estimators (2sls, gmm2s, liml), as well as additional standard errors (HAC, etc) see ivreghdfe.For nonlinear fixed effects, see ppmlhdfe (Poisson). For diagnostics on the fixed effects and additional postestimation …1-3. 2-5. Syracuse. 0-3. 4-3. Expert recap and game analysis of the Virginia Cavaliers vs. North Carolina Tar Heels NCAAF game from October 21, 2023 on ESPN.First, frequency weights just indicate how many observations a single observation should count for. If you type --help weight-- Stata will provide a clear defitinon of how frequency weights are considered. fweights, or frequency weights, are weights that indicate the number of duplicated observations.Bill Sribney, StataCorp. There are two options: (1) use correlate with aweight s for point estimates of the correlation. (2) use svy: regress for p -values. Do svy: regress y x and svy: regress x y and take the biggest p -value, which is the conservative thing to do. Consider a fixed finite population of N elements from which the sample was drawn.Feb 1, 2016 · Since this is first time I am doing survey analysis with weighted data, I am not sure whether I run the logit regs properly and some commands in stata dont work with svy syntax. For ex, I can't do factor analysis with pweight option, therefore I used aweight option. I have some questions: Is there any difference between aweight and pweight? Definitely, fweight will not work here, as it only admits weights without decimals. aweights is the one that will provide you with the standard WLS (as what you would do in a standard textbook). However, I would also consider using pweights, to get Robust standard errors.ado) calculates z-scores for the three anthropometric indicators, weight-for-age, height-for-age and body mass index (BMI)-for-age. In this macro, all available ...May 23, 2015 · aweights, fweights, and pweights are allowed for the fixed-effects model. iweights, fweights, and pweights are allowed for the population-averaged model. iweights are allowed for the maximum-likelihood random-effects (MLE) model. See [U] 11.1.6 weight. Weights must be constant within panel. Best, st: RE: Using weights with tabulate command. Date. Thu, 18 Mar 2004 16:11:10 -0000. With -tabulate-, weights are assumed to be frequency weights unless otherwise indicated. Your weights sound like analytic weights. . by country: tab illness [aw=weight01] With -summarize- weights are assumed to be analytic weights unless otherwise indicated. st: Weights with -table- and -tabulate-From: Friedrich Huebler <[email protected]> Prev by Date: st: RE: displaying date but also the time! Next by Date: st: Categorical dependent variables and large dummy variable data sets; Previous by thread: st: Weights with -table- and -tabulate-Next by thread: st: Re: Weights with -table- and -tabulate- However, when you combine multiple twoway graphs, I believe that weighting (and visual scaling of the scatters) is done relative to observations that are used in each separate twoway graph. This is not what I want; I want to weigh the scatters relative to all observations.The injected drug, tirzepatide, was approved in the U.S. in May 2022 to treat diabetes. Sold as Mounjaro, it has been used “off-label” to treat obesity, joining a frenzy …Actually, what you specify in [pweight=...] is a variable recording the number of subjects in the full population that the sampled observation in your data represents. That is, an …LONDON, Oct 19 (Reuters) - Nestle (NESN.S) on Thursday said it has started work on products to "companion" weight loss drugs like Novo Nordisk's (NOVOb.CO) game-changing Wegovy, hoping to cash in ...Jul 29, 2020 · To employ this weight named as gradient_se, I am trying to use STATA's analytical weight aweight option. But it seems like mixed command does not accept aweight option. Does anybody have any suggestion about how to incorporate these analytical weights in mixed command in any other ways? I have tried the following code but get an error: weight is derived from more than one bootstrap sample. When replicate-weight variables for the mean bootstrap are svyset, the bsn() option identifying the number of bootstrap samples used to generate the adjusted-weight variables should also be speciﬁed. This number is used in the variance calculation; see[SVY] Variance estimation. Example 2 1 Answer. Sorted by: 2. First you should determine whether the weights of x are sampling weights, frequency weights or analytic weights. Then, if y is your …I want to calculate statistics using weight like weghted mean, S.E. etc. I will appreciate if some one help me to know how to use weight in summarize command. wage weight 2000 37.40294 15000 37.0777 715 37.40294 16000 36.92306 5100 36.92306 18079 36.92306 15638 36.92306 40000 37.0777 7500 36.92306 The weighted mean should be …Stata offers 4 weighting options: frequency weights (fweight), analytic weights (aweight), probability weights (pweight) and importance weights (iweight). This document aims at laying out precisely how Stata obtains coefficients and standard er- rors when you use one of these options, and what kind of weighting to use, depending on the problem 1.Hello, I wanted to do a t-test using variables age and doctor-diagnosed asthma (ConDr) accounting also for my sample weight which is int121314. I tried thePearson Correlation: Used to measure the correlation between two continuous variables. (e.g. height and weight) Spearman Correlation: Used to measure the correlation between two ranked variables. (e.g. rank of a student’s math exam score vs. rank of their science exam score in a class) Kendall’s Correlation: Used when you wish to use ...September 18, 2013. Stata offers 4 weighting options: frequency weights (fweight), analytic weights (aweight), probability weights (pweight) and importance weights (iweight).#1 Aweight vs. fweight vs. pweight 23 May 2017, 20:45 Dear All, I am trying to estimate a treatment effect using an aggregated difference-in-difference linear regression. I have collapsed the panel from an individual level panel to treated and control (2 groups only) groups.Gestational weight change in a diverse pregnancy cohort and mortality over 50 years: a prospective observational cohort study. The Lancet, 2023; DOI: 10.1016/S0140 …Four weighting methods in Stata 1. pweight: Sampling weight. (a)This should be applied for all multi-variable analyses. (b)E ect: Each observation is treated as a randomly selected sample from the group which has the size of weight. 2. aweight: Analytic weight. (a)This is for descriptive statistics. Update 07 June 2018: See Export tabulation results to Excel—Update for new features that have been added since this original blog.. There is a new command in Stata 13, putexcel, that allows you to easily export matrices, expressions, and stored results to an Excel file.Combining putexcel with a Stata command’s stored results allows you to …Nov 16, 2022 · Clarification on analytic weights with linear regression. A popular request on the help line is to describe the effect of specifying [aweight=exp] with regress in terms of transformation of the dependent and independent variables. The mechanical answer is that typing . regress y x_1 x_2> [aweight=n] is equivalent to estimating the model: st: Weights with -table- and -tabulate-From: Friedrich Huebler <[email protected]> Prev by Date: st: RE: displaying date but also the time! Next by Date: st: Categorical dependent variables and large dummy variable data sets; Previous by thread: st: Weights with -table- and -tabulate-Next by thread: st: Re: Weights with -table- and -tabulate-wgt double %10.0g sampling weight Sorted by:. summarize Variable Obs Mean Std. dev. Min Max earnings 47,600 7848.055 4189.382 2314 103998 gender 49,771 .5547608 .4969972 0 1 educ 49,503 2.797063 1.304769 1 5 tenure 48,525 8.599588 8.934825 0 61 wgt 50,000 33.19645 61.75064 8.435029 2991.433 Ben Jann ([email protected]) dstat 2021 Stata ... Analytic weight in Stata •AWEIGHT –Inversely proportional to the variance of an observation –Variance of the jthobservation is assumed to be σ2/w j, where w jare the weights –For most Stata commands, the recorded scale of aweightsis irrelevant –Stata internally rescales frequencies, so sum of weights equals sample size tab x [aweight ...Anyway, assuming it is aweights, you can do this: Code: mean age [aweight = npatients], over (code) test A = B. where npatients is the name of the variable containing the number of patients in each study, and A and B are the value labels attached to your variable code. In the future, when asking for help with code, include example data in your ...By definition, a probability weight is the inverse of the probability of being included in the sample due to the sampling design (except for a certainty PSU, see below). The probability weight, called a pweight in Stata, is calculated as N/n, where N = the number of elements in the population and n = the number of elements in the sample. For ... Remarks and examples stata.com Remarks are presented under the following headings: Testing effects Obtaining symbolic forms Testing coefﬁcients and contrasts of margins ... [aweight=pop] (sum of wgt is 5.4190e+03) Number of obs = 65 R-squared = 0.8300 Root MSE = .025902 Adj R-squared = 0.7948

01 Feb 2016, 08:07. Dear All, Since this is first time I am doing survey analysis with weighted data, I am not sure whether I run the logit regs properly and some commands in stata dont work with svy syntax. For ex, I can't do factor analysis with pweight option, therefore I used aweight option.. Corn native american

According to Stata's help: 1. fweights, or frequency weights, are weights that indicate the number of duplicated observations. 2. pweights, or sampling weights, are weights that denote the inverse of the probability that the observation is included because of the sampling design Now, Andrea's weights are certainly not frequency weights.Jan 15, 2015 · However, the Stata tutorial states: Analytic weights—analytic is a term we made up—statistically arise in one particular problem: linear regression on data that are themselves observed means. and that is what confuses me: Here xvar is a simple size variable and neither the yvar's nor the xvar's are means themselves. Stata’s factor command allows you to fit common-factor models; see also principal components.. By default, factor produces estimates using the principal-factor method (communalities set to the squared multiple-correlation coefficients). Alternatively, factor can produce iterated principal-factor estimates (communalities re-estimated …st: RE: Using weights with tabulate command. Date. Thu, 18 Mar 2004 16:11:10 -0000. With -tabulate-, weights are assumed to be frequency weights unless otherwise indicated. Your weights sound like analytic weights. . by country: tab illness [aw=weight01] With -summarize- weights are assumed to be analytic weights unless otherwise indicated. Upload to Study. Expert Help. Study ResourcesApr 9, 2019 ... When dealing with weights, Stata has 4 different options. Frequency weights - weights that indicate the number of duplicated observations…How is Stata implementing weights? Ask Question Asked 5 years ago Modified 5 years ago Viewed 436 times 2 Consider a very basic estimation command, regress. In the manual, under Methods and Formulas, we read: So, according to the manual, for fweights, Stata is taking my vector of weights (inputted with fw= ), and creating a diagonal matrix D.I have only what you saw but my guess is as follows: (1) Start with a vector a which gives the analytic weights, and n from the sample. (2) Generate a vector w = a/sum(a) , which is normalized to sum to 1. I have learnt that since Stata 10.1, the use of analytical weights were removed due to their interpretational difficulties. When running a regression whileIntroduction reghdfeimplementstheestimatorfrom: • Correia,S.(2016).LinearModelswithHigh-DimensionalFixed Effects:AnEfﬁcientandFeasibleEstimator.WorkingPaper[weight=weight_var], and Stata will choose the correct weight. • For regressions, if you have individual data (as in the ACS,. CPS, and NLSY), use pweight ...Title stata.com vwls ... compute an OLS regression with analytic weights proportional to the inverse of the squared standard deviations:. regress y x [aweight=s^(-2)] (sum of wgt is 1.1750e+01) Source SS df MS Number of obs = 8 F( 1, 6) = 702.26 Model 22.6310183 1 22.6310183 Prob > F = 0.0000So we have found a problem with Stata’s aweight paradigm. Stata assumes that with aweights, the scale of the weights does not matter. This is not true for the estimate of sigma. John Gleason (1997) wrote an excellent article that shows the estimate of rho also depends on the scale of the weights. Logic of summarize’s formula. Now there was ...Stata で選択可能な 4 つの *weight オプション. Stata には 4 つの weight オプションがあります。. fweight: frequency weights. aweight: analytic weights. pweight: probability weights. iweight: importance weights. （ iweight は特殊なオプションとのことで、この記事ではそれ以外の 3 つを扱い ...Actually, what you specify in [pweight=...] is a variable recording the number of subjects in the full population that the sampled observation in your data represents. That is, an observation that had probability 1/3 of being included in your sample has pweight 3. Some researchers have used aweights with this kind of data..

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