Two economists have just published a working paper on the economic factors behind parents in Italy deciding to castrate a son. The paper is available to either read on-line or to download from the European Center for Advanced Research in Economics and Statistics at the Université libre de Bruxelles. One author, Victor Ginsburgh, has a joint appointment with the Center and also with the Center for Operations Research and Econometrics at the Université Catholique de Louvain. The other author, Luc Leruth, is with the International Monetary Fund.

While I would quibble with some of the history that they include, their economic analysis is quite convincing.

You can read or download the paper from the ECARES site:

https://ideas.repec.org/s/eca/wpaper.html

Once you are on the page, scroll down to paper 2017-15: The Rise and Fall of Castrati. Click on the paper title.

I am reminded of Anne Rice's book, Cry to Heaven. which also dealt with those singers.

It is a very good book, the istoria is very interesting