demand for images

The magic lantern was the first device that could display at zero marginal cost many large images to large groups of persons. Magic lanterns were for sale in London as early as 1663. They projected an image on a glass slide through a lens to a distant screen.  By the nineteenth century, magic lanterns had became a popular means for displaying images in a wide variety of circumstances.  The success of the magic lantern, like the rapid rise of commercial photography, indicates high popular demand for images.

magic lantern used by itinerant lantern showmen

In eighteenth-century Europe, itinerant “showmen” offered shows using magic lanterns.  The early showmen in London were called Galantee showmen or Savoyards.  These names suggest that they were predominately foreign.  By 1788, Galantee showmen were sufficiently well-recognized in London to be used by a leading caricaturist to satirize a leading political figure.  He was depicted “exhibiting, by means of a magic-lantern, the magnified figures of different objects on the wall.”[1] The above image shows a wooden magic lantern that itinerant showmen used. It included protected storage and display spaces for the glass slides and was carried on the showman’s back.[2]

Projected-image shows began in Japan in 1803. Called utsushi-e, they employed multiple, hand-held projection devices (furo) made of wood. The Minwa-za Company of Tokyo has brilliantly recreated utsushi-e performances. The above video clip, from a Minwa-za Company performance, suggests the popular appeal of utsushi-e.[3] Compared to glove puppet shows, utsushi-e performances are starker — the lit figures contrast sharply against the black background and change discontinuously with the switching of the glass slides.

By the mid-nineteenth century, magic lanterns spanned a wide range of business possibilities.  About 1850, a street worker in London remembered his work in the 1830s:

A month before Christmas … we went with a galantee show of a magic lantern. We showed it on a white sheet, or on the ceiling, big or little, in the houses of the gentlefolk and the schools where there was a breaking-up; it was shown by way of a treat to the scholars. There was Harlequin, and Billy Button, and suchlike. We had 10s. 6d. and 15s., for each performance, and did very well indeed. I have that galantee show still, but it brings in little now. … The galantee show don’t answer, because magic lanterns are so cheap in the shops. When we started, magic lanterns wasn’t common, but we can’t keep hold of a good thing long in these times. It was a regular Christmas thing once – the galantee show. I can make, in a holiday time, 20s. a week at present; but that’s only at holiday times, and is just a mere casualty a few times a year.[4]

To compete with the cheap, popular magic lanterns available in stores, successful magic lantern shows invested more in their shows — more powerful lanterns, better quality slides, and well-practiced musical and acting routines as part of the show.  In London, the most highly capitalized show was at the Royal Polytechnic Institute:

From 1838 to 1876, the Polytechnic produced extraordinary shows that dazzled two generations. The shows used giant lanterns with slides that were sometimes two feet long. Over 900 “Polytechnic” slides were exquisitely painted by the specialist firm of Childe and Hill, and Childe’s dissolving views and elaborate special effects were an important part of the shows’ popularity. The program was changed regularly during the year and included battlefront reports of the current wars, and fairy tales such as “Aladdin’s Lamp.” The highlight of the year was The Christmas Special, featuring (of course) Dickens’ classics like “Gabriel Grubb.”[5]

Following the first public use of limelight — intense white light thrown off from limestone heated in an oxygen-hydrogen burner — in the Covent Garden Theatre in London in 1837, powerful magic lanterns like the Polytechnic’s put lantern slides “in the limelight”.

Magic lantern shows were highly popular in the U.S. At the end of the nineteenth century, there were 30,000 to 60,000 lantern showmen.  For comparison, in 1900 about 27,000 persons were photographers, and about 36,000 persons in total were journalists, authors, and scientists. [6]  Measured by employment, putting on image shows was a bigger business than photographing and writing.  Public libraries collected and circulated lantern slides. In 1914, well past the peak popularity of magic lanterns, 6% of items circulated from the Cincinnati Public Library were lantern slides.  Vast numbers of lanterns slides have survived to the present time.  At the Magic Lantern Society’s recent Thirteenth International Magic Lantern Convention, many magic lanterns slides from the early twentieth century could be bought, some for as little as a dollar.

magic lantern slides for sale at the Magic Lantern Convention


[1] James Sayer’s caricature of Edmund Burke, as described in The Gentleman’s Magazine, March, 1849, p. 238.

[2] Deac Rossell presented and described this image in his fascinating presentation, “Laterna Magica,” at the National Gallery of Art, July 13, 2008. Rossell emphasized that the device was well-designed to meet the particular needs of itinerant showmen.

[3] From The Minwa-Za Company of Tokyo’s performance of “Daruma Yawa” at the Freer Gallery, Washington, DC, July 10, 2008. Machiko Kusahara offers much information about utsushi-e at the Media Art Plaza.

[4] From Henry Mayhew, The Morning Chronicle, Labour and the Poor, 1849-50, Letter LII, May 16, 1850.

[5] From Terry Borton, “Traditional Holiday Magic Lantern Shows,” Bulletin of The League of Historic American Theaters, Nov. 1998, available here.

[6] Id. is the source for the estimate of lanternists.  The figures for photographers, journalists, authors, and scientists are from the U.S. Census of 1900.  For occupational census counts for photographers and authors (and related occupations) from 1850 to 2000, see Tables C1 and C2 in Galbi, Douglas (2003), “Copyright and Creativity: Photographers and Authors.” The American Magic-Lantern Theater recreates high-quality U.S. magic lanterns shows from the 1890s. See trailer.


You can tell a man’s age
by the count of blankets
like the rings of a tree
that wrap around him,
by the width of his bark,
by the thickness of the life
that will flow from his heart
if you tap it.

debating the long tail

Getting a good, well-understood model often takes you three-quarters of the way toward solving a class of problems. Persons’ choices among a large number of symbolic items still lacks a good, well-understood model for business analysis.

Among a set of similarly instantiated symbolic items in a given domain of choice, item popularity vs item rank in log-log coordinates typically can be well described by a straight line.  Put differently, a power-law distribution typically provides a reasonably good model for the aggregate pattern of choices. In a comment referring to a graph of Facebook app popularity, Chris Anderson seems to describe his Long Tail theory as equivalent to observing a straight line in log-log space:

A Long Tail is a powerlaw distribution, which looks exactly like what you’ve shown. All powerlaws have a huge drop-off like that–but the tail being long (get it?) the area under what appears to almost nothing adds up to a lot. The only way you can tell whether it really does conform to the theory or not is to plot it log-log and see if it’s a straight line.

At least under one definition of heavy-tailed distribution, all power laws are heavy-tailed. This meaning of heavy-tailed largely concerns the interpretation of observables and the management of risk.  Heavy-tailed distributions are associated with rarely observed, difficult-to-predict outcomes that can dominate values of concern, such as aggregate profits.  From this perspective, power laws and other extreme-value distributions are characteristic features of blockbuster-oriented, highly unpredictable businesses.[1]

As Anand Rajaraman insightfully observes, the Internet has produced powerful tools for communicating among persons and for observing and aggregating users’ choices and ratings.  The process that produces blockbusters now depends more on influence among users.  Experiments indicate that increasing social influence increases the unpredictability of success.[2]  But even when blockbusters depend on more centralized, directed marketing campaigns, blockbusters have always been highly unpredictable.[3]

The slope of the approximating straight line for item popularity vs item rank in log-log coordinates offers a rough means for distinguishing between a blockbuster-oriented business and a niche-oriented business.  The less the absolute value of the slope, the more business is distributed across relatively low popularity items.  An even simpler index is the popularity of the most popular item.  That’s the intercept of the item-popularity vs item-rank line where the x-axis goes from 1 to the number of items available.  But this extremely simple index ignores most of the data: unusual circumstances may determine the popularity of the most popular item and make the approximating line fit badly for the top-ranked item.  Thus the slope of the approximating line is probably a better, simple description of the business.[4]

Evidence is mixed on the evolving importance of blockbuster businesses relative to niche businesses in symbolic economies. Because a large number of possible names has been freely available since the invention of language (supply side), studying the distribution of chosen names is a good way to isolate demand-side factors in mass symbolic choice.  In England over the past thousand years, given names show a remarkable flattening in the approximating power law beginning about the time of the Industrial Revolution and continuing to the present.  On the other hand, experiments indicate that increasing social influence increases the steepness of the slope, meaning social influence makes popular items relatively more popular. [5] The Internet is plausibly associated with greater social influence, which may be sufficient to reverse apparent long-term trends toward diversification in symbolic choices.

A recent study of business data would have made a greater contribution to understandings symbolic economics with more attention to defining useful statistics. The study reported that among more than a million tracks offered through Rapsody in 2006, “the top 10% of titles accounted for 78% of all plays, and the top 1% of titles for 32% of all plays.”  For just under 16,000 movie titles offered through Quickflix in 2006, “the top 10% of DVDs accounted for 48% of all rentals, and the top 1% for 18% of all rentals.”[6] A problem with these statistics is that the total number of titles on offer is changing greatly.  Hence statistics such as the “top 10% of titles” and “the top 10% of DVDs” lack enduring significance.  Because humans have physically limited brains and communication capabilities,  rapidly increasing the total number of symbolic items that persons could choose isn’t likely to affect the aggregate pattern of actual choices among relatively popular items.

Nielsen VideoScan indicates an increasing number of titles are rarely chosen:

The number of titles that sold only a few copies almost doubled for any given week from 2000 to 2005. In the same period, however, the number of titles with no sales at all in a given week quadrupled. Thus the tail represents a rapidly increasing number of titles that sell very rarely or never. … Moreover, we determined that this is not simply a function of the sharp increase in the number of titles that have come onto the market in recent years, or of the transition from VHS to DVD; it is the truth of the long tail.[7]

The author did not describe how the analysis separated the effects of the sharp increases in total titles from actual choices. Disentangling the effects of an increase in titles is a difficult problem. That the form of the author’s statistics depend strongly on the total number of titles suggests that the author hasn’t actually figured out how to do that.

Some data indicate a growing business in a small number of titles.  With respect to Nielsen Videoscan data:

success is concentrated in ever fewer best-selling titles at the head of the distribution curve. From 2000 to 2005 the number of titles in the top 10% of weekly sales dropped by more than 50%—an increase in concentration that is common in winner-take-all markets.

The effect seems not to be consistent with a linear popularity model.  With respect to Nielsen Videoscan data, the author observes:

The importance of individual best sellers is not diminishing over time. It is growing.

But with respect to Nielsen Soundscan data, the author notes:

although today’s hits may no longer reach the sales volumes typical of the pre-piracy era, an ever smaller set of top titles continues to account for a large chunk of the overall demand for music.

If individual hits decrease in popularity, but an ever smaller set of top titles continues to account for the same large share of demand, than a linear popularity model doesn’t describe well what’s happening. Perhaps the decrease in sales volume for hits (individual best-sellers) refers to a decrease in the overall demand for (commercially sold) music.

The aggregate characteristics of persons’ choices among a nearly infinite set of symbolic goods isn’t well-understood.  But the importance of such choices clearly is increasing.  As is conventional, I’ll end this post with a call for more research, and for more support for regulators.

*  *  *  *  *


[1] See De Vany, Arthur S. Hollywood Economics: How Extreme Uncertainty Shapes the Film Industry. Contemporary political economy series. London: Routledge, 2004, and Taleb, Nassim. The Black Swan: The Impact of the Highly Improbable. New York: Random House, 2007.

[2] See Matthew J. Salganik, Peter Sheridan Dodds, and Duncan J. Watts, “Experimental study of inequality and unpredictability in an artificial cultural marketScience, 311, 854-856 (2006).

[3] Extensive marketing and promotion may be necessary for traditional-media blockbusters, but it is not sufficient.  See, e.g. De Vany (2004).

[4] Viewed as a distribution of popularity shares, a power-law approximation for item popularity vs. item rank has only one free parameter.  The minimum item rank is necessary one (the most popular item) and the total popularity shares must sum to one. But remember that an approximating line is a model, a tool for analysis, a means for organizing fruitful comparison and discussion. The slope of a linear approximation to the popularity distribution for a range of items of practical interest seems to me to best serve this purpose.

[5] Salganik, Dodds, and Watts (2006).

[6] See Anita Elberse, “Should You Invest in the Long Tail?” Harvard Business School Review, July-Aug. 2008.

[7]  This and subsequent quotes are from Elberse (2008).

games need regulation

To increase my regulatory expertise, I recently attended a four-day VHSL Basketball Officials Camp.  The camp included both class sessions with top officials and on-court practice. The supervising officials provided extensive feedback on mechanics and calls.  One supervising official told me bluntly to drop my laissez-faire approach and put some air in my whistle.  By the end of the camp I was more actively managing the competition.  Overall, the camp was excellent.  It made me a better official.

Better officials benefit all players.  Better officials make for better games.