How automated estimates work and what they are for
Various software tools and artificial intelligence models make it possible to obtain an economic estimate in a few seconds from a photograph and brief descriptive data. These systems draw on the archives of international auction sales, cross-referencing data on the artist, medium, dimensions and year of execution to arrive at a probable value. They are legitimate and effective tools for rapid market analysis: they show how many works by an artist change hands, sales volumes and the general trend in prices.
The structural limits of algorithmic analysis
The main obstacle for these tools lies in their inability to grasp the particular features of the physical work. An algorithm processes only reference data and information supplied by the user, without being able to verify its truthfulness. Specifically, the software cannot:
- Verify the actual condition of the work or the presence of invasive restoration beneath the surface.
- Examine the signature, materials and technique in person, verify the work's actual inclusion in an archive or catalogue raisonné, or trace its provenance.
- Distinguish, in terms of quality, between a successful example and a mediocre one within the same series, a difference that has a decisive bearing on value.
- Define the intended use of the estimate (fair market value, replacement value or net realisable value).
- Select the source data: auction results are often incomplete or inconsistent (condition not stated, prices with or without premium, charity sales), and the appraiser compares them across several sources.
Automated analysis gives acceptable results on serial, homogeneous goods, for which many comparable data exist, and shows all its limits when faced with the uniqueness of a work of art.
The substantive difference from an appraisal
Unlike a report generated by software, an appraisal is the outcome of the direct examination of the work and of documentary and market research conducted by a professional. The appraiser selects the comparables and gives reasons for the choice, applies a rigorous methodology and states the purpose of the document. Above all, the appraiser answers for their own work: they sign the document, state its limits and assumptions and may be called upon to justify their conclusions to those who use it; an algorithm answers to no one and cannot be called upon to justify its estimate.
For these reasons, an automated estimate cannot replace an appraisal when the value must stand up before third parties: in the division of an estate, for insurance cover, for a loan secured on works of art or in a dispute.
A proper use of digital platforms
The ideal use of these tools is informative and preparatory: a collector may consult the platforms before instructing an appraiser and submit the data gathered to the appraiser, who will assess whether and how to integrate them into the comparative analysis.