I have complained many times over the last two years that the historical loan data on Prosper was far too complex for the average investor to work with. Until now the data has only been available in XML format or through the API. That is why I have always relied on the third party sites like Prosper Stats, and before them Lendstats, to do analysis of the Prosper history.

Yesterday, Prosper simplified their data download and at the same time made some major changes to what is available.  The details are described on their blog here. While the changes are a vast improvement there is now a huge amount of data to wade through. The good news is that the data is available in the easy to use CSV format so the files can be opened in Excel.

There are four new files available and here is an explanation of each one.

1. Expanded Underwriting Archive

This CSV is compressed in a Zip file because it is so large. This file when uncompressed is 340 Megabytes and contains very detailed credit information on loan listings dating back to July 2008. And when they say detailed information they mean it. There are 558 data points for more than 118,000 loan listings so you can see why it is a big file. Not all of these listings became loans and many would not make it on to the platform today but it provides a big base of information to work from.

2. Expanded Underwriting Attribute Data Dictionary

This Excel file contains an explanation of all the fields in the Expanded Underwriting Archive and Recent Listing Sample.

3. Loan Data Export

This file is the equivalent of the historical data download at Lending Club. It contains detailed information on every loan going back to day one. With just 55 fields it doesn’t have all the data points of the Expanded Underwriting Archive but investors will recognize many of the fields here. I imagine this file will be the starting point for many investors. Most of the fields in the Loan Data Export are self-explanatory but I have been told a data dictionary is coming for this file as well.

4. Recent Listing Sample with Expanded Underwriting Data

A subset of the loans available at Prosper has this expanded underwriting information and these are included here. It is important to note that this is not a real time file and at the moment the intention is for this file to be updated once a week. The purpose of this file is to provide sophisticated investors with a complete credit dataset that can be used to make more intelligent investing decisions.

So there you have it. All these files are available on Prosper’s new Download page. For the data and credit junkie you now have more information than ever before. I had no idea there was this much data available on borrowers and that some investors were demanding it.

One of the advantages for the average investor is that we will now be able to do an apples to apples comparison between Lending Club and Prosper data. It will be interesting to see how this information will be used by the many p2p lending statistics sites. I expect we will see some really useful tools launch soon to help investors use this new information.