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Estimating the Loss of Medieval Literature with an Unseen Species Model from Ecodiversity

The century-long loss of documents is one of the major impediments to the study of historic literature. Here we focus on Middle Dutch chivalric epics (ca. 1200-1450), a genre for which little archival records exist that shed light on the survival rates of works and documents. We cast the quantitative estimation of these survival rates as a variant of the unseen species problem from ecodiversity. We apply an established non-parametric method (Chao1) and compare it to a number of common alternatives on simulated data. Finally, we discuss the implications of our results for conventional philology: our numbers suggest that the losses sustained on the level of works may be more dramatic than previously imagined, whereas those at the document-level align surprisingly well with existing estimates in book history, although these were based on completely different data sources.