Here's part of the abstract:
Contending that current theories of cross-cultural transmission are inadequate, this study examines the reconstruction of the Western romance novel formula by Nigerian authors. It finds that some elements of the Western formula, such as the characterization of the female protagonist, are continuous with the Western model, while others are radically changed. For example, while Western romances center on a single love interest and ‘end happily ever after’, Nigerian romances often involve the protagonist in several love affairs, and may have inconclusive or tragic endings.
The problem I can see with this argument is that "the Western formula" they refer to is drawn from Radway and Modleski and the two sample texts used as examples of "the Western formula" were published by Harlequin and Silhouette. It therefore doesn't take into account the existence of Western "romantic fiction" which is not "romance." In the US this would include authors such as Danielle Steel and in the UK "sagas" such as Catherine Cookson's have been popular.