Maria, I don't know of references off-hand, but it seems like a bad idea on the face of it.
Do I understand correctly that the analysts are wanting to give a single value to all missing data, and then analyze? That's making two very strong and implausible assumptions: that all the missing values represent the same level of income, *and* that you know with precision what that value is. (Multiple) imputation represents a balance between what you can be fairly sure of -- a general idea of income based on the other variables -- and uncertainty around that general idea. Hope that helps, Pat On Sat, Jul 4, 2009 at 9:19 AM, Maria da Conceicao-Saraiva<[email protected]> wrote: > > > > Sorry about this question, > > I have been discussing with some people I am working about the need of > imputation with some of our data. What some of analysist are doing is just > to creating a category of missing values inside some variables, they argue > this is enough. It has been hard to argue with them that this is not the > best way to do. Specially in our variable income, we have about 30% of > missings. > Does anybody know about ?refereces discussing this approach of just creating > a category for missing values inside a variable? > > Maria > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Maria da Conceicao P. Saraiva DDS, MSc, Ph.D > Departamento de Clinica Infantil e Odontologia Social e Preventiva > Faculdade de Odontologia de Ribeirao Preto-Universidade de Sao Paulo > > ?Aviso: Esta mensagem destina-se exclusivamente ao destinatario, sendo > ?confidencial. Se V. Sa. nao eh o destinatario, fique advertido de que a > divulgacao, distribuicao ou copia desta mensagem eh estritamente proibida. > Caso tenha recebido esta mensagem por engano, por favor avise > imediatamente seu remetente atraves de resposta por e-mail. Obrigado. > ________________________________________________________ > Warning: This message is intended exclusively for its addressee and > contain confidential information. If you are not the addressee, you are > hereby notified that any dissemination, distribution or copying of this > communication is strictly prohibited. If you have received this > communication ?by mistake, please immediately notify the sender by reply > transmission. Thank you. > > > > _______________________________________________ > Impute mailing list > [email protected] > http://lists.utsouthwestern.edu/mailman/listinfo/impute > -- Patrick S. Malone, Ph.D., Associate Professor Department of Psychology University of South Carolina http://people.cas.sc.edu/malonep/ Yahoo Messenger: patricksmalone AOL Instant Messenger: pat2048
