Notes to Reviewers of the paper:

"On the Calculation of the Prevalence of Transsexualism"

By Femke Olyslager and Lynn Conway

September 6, 2007

[V 9-11-07]


We have submitted the following paper for publication in the International Journal of Transgenderism (IJT). In addition to the formal peer reviews conducted by the IJT, we would appreciate others’ help in critical evaluation the paper – in an effort to refine the paper thoroughly prior to its publication.


Olyslager, F. and Conway, L., “On the Calculation of the Prevalence of Transsexualism”,

presented at the WPATH 20th International Symposium, Chicago, Illinois, September 6, 2007


This page provides information that may be helpful to reviewers of that paper. We include here our contact information, links to tutorials on the mathematics used in our paper, links to related work in progress. Lynn Conway has also provided links to the originals (PDFs) and summaries of the data and results of the key past papers. Those links will enable reviewers to read those papers in the original, and thereby confirm our analyses of the data and results in those earlier papers.


Reviewers may also benefit from a study of the powerpoint slides used to present the paper at the WPATH Symposium (along with the included speaker's notes); those slides contain a concise version of the basic logic, calculations and results of the paper:


If you have any questions or comments about our work, please feel free to contact us at the e-mail addresses below. We would greatly appreciate your feedback on our paper.


Femke Olyslager and Lynn Conway





1. Authors’ contact information:


Professor Femke Olyslager, Ph-D.

Department of Information Technology,

Ghent University,

Sint-Pietersnieuwstraat 41, 9000 Ghent, Belgium.

E-mail Femke


Professor Lynn Conway

3640 CSE Building,

University of Michigan,

Ann Arbor, MI 48109-2121 USA

E-mail Lynn



2. Links to tutorials on the mathematics used:


The Wikipedia contains useful tutorials on the areas of mathematics involved in this paper, and on the key topics of demographics and epidemiology too. Although Wikipedia remains controversial as a source of information on people and events, it can prove valuable as a source for tutorials in non-politicized areas such as mathematics:


Set theory and discrete mathematics:


Probability theory:




Estimation theory







3. Related work in progress:


There are two related works underway in support of this paper:


The first is an internet-based interactive report by Lynn Conway that provides direct access to all the old key reports on the prevalence of transsexualism, and that uses a series of spreadsheet tables to present normalized cross-comparisons and analyses of the results of those papers – using the notation and methodology developed in this paper.


[Conway07] L. Conway, "A comparative analysis of reports on the prevalence of transsexualism”,, September 6, 2007


The second report will contains a summary of the definitions and notation and mathematical methods in this paper, and extensions of those methods to cover more general cases involving mortality effects and other second-order effects.


[Conway and Olyslager07] L. Conway and F. Olyslager, “Calculation of the prevalence of transsexualism and related caregiving: Definitions, notation, key equations and analytical methodology“,, (in progress) [Date and URL TBD]



4. Links to originals (PDFs) and summaries of the results of key past papers:


For the convenience of readers and researchers, Lynn Conway has provided access in her website to online versions of each of the earlier reports on the prevalence of transsexualism (including some papers not referenced in the WPATH conference paper). Many of those reports are historical ones, and have not been read in decades by researchers in the field. Those online papers will help reviewers follow and confirm the analyses in our paper (Olyslager and Conway, 2007).


You will find links to PDF’s of the papers in the following table (in chronological order), along with links to summaries of results of each paper (click on the ‘X’s). These links will enable reviewers to read the papers in the original, and confirm for themselves the methods, data and results presented in those papers: 











eklund88 '80