Analyzing art investment has two major obstacles. The first is the relative lack of data, as art sales happen much less frequently than financial trades. The other is that every piece of art is different, so it becomes difficult to compare how one piece sells with respect to another. 

One way to develop a view of the market despite these challenges is to develop an index–  a set of values over time that can show market movements and trends.

While no single art index perfectly captures every factor that influences art valuations, art indices play a significant and growing role in helping investors better understand the art market. 

For individual collectors, these benchmarks can be invaluable for spotting art market trends, drawing correlations between art and other asset classes, and making more informed decisions about owning fine art.

Why Are Art Indices Important?

Art Indexes are meant to mitigate any opaqueness in the art market. Typically public art sales occur on a seasonal basis, while regular financial markets occur more frequently. Aside from that, much of this data is kept private through private sales or because of confidentiality laws in place. With Indices, there’s much more transparency about the market for other collectors and investors to base decisions on. 

Also, art valuation and pricing are contingent on multiple variables based on the piece of work, particularly size, media, subject matter, etc. All of this isn’t easy to digest and analyze as a whole. Art Indices provide ease for analyzing the value and demand of comparable artworks and artists. 

Acquired in 2016, the Sotheby’s Mei Moses Indices are widely recognized as the preeminent state-of-the-art market measure.

What are the Mei Moses Indices?

Leveraging over 80,000 repeat auction sales for the same piece over time, Sotheby’s can produce objective art market analyses to complement the world-class expertise of its specialists.

Developed in 2002 by New York University Stern School of Business Professors Jianping Mei, Ph.D. and Michael Moses, Ph.D., the Sotheby’s Mei Moses indices control for differing quality, size, color, maker, and aesthetics of a work of art by analyzing repeat sales.

Sotheby’s Mei Moses Indices can be used to compare the performance of art subcategories, identify trends and internal dynamics of the market and understand the market’s relationship to broader economic and societal factors. The methodology is based on the Case-Shiller Real Estate Index.

What Is A Repeat Sale?

A repeat sale, according to Sotheby’s Mei Moses Indices, compares changes in sale prices of the same artwork at specific points where the painting is sold.

The Mei Moses Indices track all live and online auction sales at Sotheby’s, Christie’s, and Phillips for artworks that previously sold at public auction, going back roughly 200 years.

The index creators reasoned that repeat sales are a better way to track price trends for unique objects, such as art because they express price changes of the specific underlying assets rather than the average or median for the market. This helps minimize the effects of infrequent trading, reporting biases, or characteristic differences that can skew the data. 

Drawbacks of the Mei Moses Index

While this methodology provides a sound apples-to-apples comparison of valuation changes, the tradeoff is that it represents a tiny percentage of the art market—namely higher value works of art.

Hence, these indices need to expand to track the vast majority of the market. 

What Are Other Art Indexes?

Masterworks

At Masterworks, we offer an extensive Price Database that is free and available for anyone to access. The Masterworks Price Database comprises over 3 million data points featuring over 300,000 artists in order to compile a comprehensive center for artist market appreciation.

The database also follows the methodology of Mei Moses using repeat sales to determine the estimated price appreciation of Modern and Contemporary artworks and their artists’ markets from auction records tracing back to the 1960s.

Artnet

In addition to custom indices, Artnet tracks seven standard indices: Top 100 Artists, European Old Masters, Impressionist Art, Modern Art, Post-War Art, Contemporary Art, and Chinese Art and Artist Indices.

The company’s indices are based on its extensive Price Database, which covers more than 1,800 auction houses and 340,000 artists, featuring art auction data from 1985.

This methodology’s reliance on self-reporting from market participants is a possible drawback. Fluctuations in reporting or changes in the underlying characteristics of the art sold in any given period can skew the results.

Wondeur

Where the Artnet and Mei Moses indices focus on actual public sale data, Wondeur uses artificial intelligence to recognize pricing patterns.

The AI is used to recognize pricing patterns for over 240,000 artists and is based on analysis of non-transactional drivers of value in the art world, including influence from museums and galleries.

Benefits of Art Indexes

As stated previously, all art indices, like the Mei Moses Indices, can provide a benchmark of data sets for art investors, financial advisors, and art market researchers to better understand the art market.

With an art market index, users can make more educated decisions on art investment by providing a more explicit scope of art market trends and art prices through macroeconomic dips and highs.

Drawbacks of Art Indexes

Art indexes do have their limitations, to be sure. Art is a large, heterogeneous and unregulated market in which more than half of all sales are private. The unique qualities of a work of art, including its provenance and condition, affect individual prices—and ever-changing tastes greatly influence valuations. Moreover, most art indices don’t include works that fail to sell.

The Bottom Line

Despite these challenges, art indices have evolved significantly over the last several decades, thanks to better data and improved methodologies. And as these benchmarks improve, they are increasingly helping collectors understand the value of what they own, identify pricing trends and make better decisions about owning and planning around their art.