Thank you for all the comments and questions.  Here is some background for you on the resolution quality of Sanborn Maps. 

As many of you know, Sanborn Maps were originally produced by the Sanborn Map Company as hardcopy books and distributed to insurance companies across the United States.  The early hardcopy books included multi-color coding, generally used describe building construction materials such as “Frame building”, “Stone building”, and “Brick building.”  Later in the 20^th Century, many Sanborn Maps were converted entirely to black and white, and color coding was converted to text labels, which helped to improve the efficiency of making maps and accommodated the growing use of Mylar materials, although even up to recently the Sanborn Map Company has continued to produce some color maps using water color inks applied by hand.  Toward the end of the 20^th Century, the hardcopy maps were photographed and the images were reproduced in black and white on microfilm.  At that time, black and white microfilm was the standard in image reproduction.  Several years later, the complete Sanborn Map microfilm collection was scanned by EDR at very high resolution, enabling EDR to deliver very high quality digital images for use by our customers. Digital electronic images of the Sanborn Map Library collection are now searched and delivered quickly by EDR through email as PDF documents, a document format developed by the Adobe Corporation to enable the efficient transfer of documents between computers that might be using different types of software.  PDF documents are extremely good at compressing large files into a very manageable size. When EDR introduced the high resolution scans of the complete Sanborn Map Library a few years ago, we paid very special attention to making sure the PDF compression did not alter the quality and utility of the images, bearing in mind that our customers would still require us to minimize the file size to enable them to store documents and efficiently deliver Sanborn Maps via email.  EDR invested a substantial amount of time to use the latest technology and best file types to deliver optimal results.

As an example of the quality of images delivered by EDR, compare the source image below to the image in the final PDF (the location is from a 1950 map on the corner of N. Dearborn and W. Hubbard in Chicago). Bear in mind that even though both images are black and white, the source scanned image is still 10 times larger than the actual delivered PDF, and therefore, were EDR to deliver the source images, the files could easily bog down anyone’s email inbox. The file size difference between scan and PDF becomes particularly important when considering the additional images included when searching the complete Sanborn Library collection.

Going foward, as newer technologies and file compression methods become available, our future goal is to create an interactive viewer to access and deliver the highest quality image possible.  As usual, EDR continues to research ways to improve every product we deliver and we appreciate your feedback throughout this thread. 

Thanks again, Paul.

Interesting. While it is true that the cost of computers has gone down (see Moore's Law and the Producer Price Index from the BLS), in many cases the price a consumer actually pays "out-of-pocket" for a computer (the observed price) has stayed pretty much the same for many years.

Take, for example, the computers sold by Apple.  The flagship Apple Mac Plus product cost $2599 when it was introduced in 1986 -- in today's dollars, that's $5,174. These days, Apple lists its top of the line Mac Pro with monitor for $5098.  25 years later, the price a consumer pays for a top of the line Mac remains almost exactly the same. 

Another example from Apple: the IPod in 2001 cost $492 in today's dollars; the IPad of today costs $499; a new IPhone without the contract subsidy costs $499 - $699.

This same pricing model holds for Microsoft PC's as well.  The first IBM PC, released in 1981, typically sold for $3000 for home use, or $7200 in today's dollars.  Remember, this was the top of the line IBM home computer at the time.  Today, the top of the line Windows Dell home gaming computer can be purchased for well over $7200, assuming you order the most modern componants available. So, in this case, prices have actually increased, rather than decreased.  Furthermore, even low end prices for computers running Windows have held steady at slightly above $1000 for years, assuming you get the popular technology of the day like speakers, wireless, and a decent monitor.

Of course, actual prices for directly comparable component technology have gone down geometrically, due to competition and innovation, but the demand for new features has helped keep actual out-of-pocket prices fairly steady in comparison, and the consumer continues to pay the same amount for the standard accepted technology of the day.

The story doesn't end there, though. While component prices for similar goods have been decreasing, at the same time overall corporate technology spending has been increasing substantially. Corporations continue to invest in new computer technology at growing rates.  For details, see this excellent series of several articles from Harvard Business Review. 

In short, an economic model based on what happens in the the computer industry has three possible structures:

1. A model of improving features but steady prices for final to market products

2. A model of increasing corporate spending on the technology

3. A model of rapidly declining prices for directly comparable parts and components

Now, back to the Phase I market. If you are saying that Phase I pricing is following some normative economic model analogous to computers sold to consumers and corporations, then it seems you ought to be saying that actual Phase I pricing should be holding steady and that the features offered in the Phase I should be improving over time. You also ought to say that total corporate spending on environmental due diligence should be increasing, again following the computer model. 

But, that is not what you are saying.  You seem to be saying that, as if it were similar to the parts and components of a computer, Phase I "components"  go down in price as raw materials and production processes improve under the steady pressure of competition. But this is odd thing to say: the main cost component of a Phase I is simply the professional service provided, and services, like all consulting relying on highly qualified people, are much more resistant to pricing reductions than material components, because its much more difficult to get large cost reductions from U.S. labor than from a material object that can be produced overseas or from a software product where development can be tightly streamlined.  In any event, with professional services, short of overseas outsourcing, you certainly cannot get the same kind of geometric price reductions found in the computer component industry. Needless to say, it seems unlikely that Gordon Moore intended to include environmental due diligence in his famous formulation about computer processing power.

In summary, while there is an economic story here to be told about Phase I ESA pricing pressure, competition and quality, it seems that an analogy with a computer isn't the clearest way to tell it.