Does Pope Francis write the books ascribed to him, or are they ghostwritten?

Does Pope Francis write the major literary works ascribed to him or are they ghostwritten?

The short answer is: Pope Francis is the author of these works.

Before going on, it should be stated that the Evangelii Guadium (Joy of the Gospel) is an Apostolic Exhortation on the Proclamation of the Gospel in Today’s World. Pope Francis has also written two encyclicals Lumen Fidei and Laudatio Si.

Given the definition of what apostolic exhortations and encyclicals truly are, it would be doubtful that they were ghostwritten.

Definition of an encyclical:

A papal document treating of matters related to the general welfare of the Church, sent by the Pope to the bishops. Used especially in modern times to express the mind of the Pope to the people. Although of themselves not infallible documents, encyclicals may (and generally do) contain pronouncements on faith and morals that are de facto infallible because they express the ordinary teaching of the Church. In any case, the faithful are to give the papal encyclicals their interior assent and external respect as statements of the Vicar of Christ. (Etym. Latin encyclicus; Greek enkyklios, circular, general.)

An encyclical epistle is like an encyclical letter but addressed to part of the Church, that is, to the bishops and faithful of a particular area. Its contents may be doctrinal, moral, or disciplinary matters of universal significance, but may also commemorate some historical event or treat of conditions in a certain country or locality. - Encyclical

Definition of an apostolic exhortation:

An apostolic exhortation is a type of communication from the pope, the head of the Catholic Church. It usually encourages a community of people to undertake a particular activity but does not define Church doctrine. It is considered lower in formal authority than a papal encyclical, but higher than other ecclesiastical letters, apostolic letters and other papal writings.

Apostolic exhortations are commonly issued in response to an assembly of the Synod of Bishops, in which case they are known as post-synodal apostolic exhortations. - Apostolic Exhortation

Thus given the nature of these works, they are in fact written by the pope himself, since they express the mind of the Holy Father in regards to the Universal Church.

That said, it is known that popes take insight from others when writing major works. For example, before the dogmatic definition on the Assumption of Mary in Deiparae Virginis Mariae, Pope Pius XII sought the opinion of Catholic Bishops.

In his encyclical Lumen Fidei, Pope Francis acknowledges the helpfulness of Pope Benedict XVI in creating a first draft of this major literary work. It should be noted also that contrary to common belief, the encyclical is not co-signed. After all, Pope Francis is the Sovereign Pontiff, not Pope Emeritus Benedict XVI:

7. These considerations on faith — in continuity with all that the Church’s magisterium has pronounced on this theological virtue — are meant to supplement what Benedict XVI had written in his encyclical letters on charity and hope. He himself had almost completed a first draft of an encyclical on faith. For this I am deeply grateful to him, and as his brother in Christ I have taken up his fine work and added a few contributions of my own. The Successor of Peter, yesterday, today and tomorrow, is always called to strengthen his brothers and sisters in the priceless treasure of that faith which God has given as a light for humanity’s path. - Lumen Fidei

This all said, not all homilies pronounced by a pope are written by the Holy Father himself. For example, Pope John Paul II visited the Archdiocese of Vancouver, September 17-19, 1984. His homily of his at Abbotsford International Airport was written by a local priest of the archdiocese: Mgr Richard Mugford.

I can still recall Mgr Mugford telling me that this “so called privilege” cost him countless sleepless nights.