WSJ Housing Inventory Trends

Check out this Wall Street Journal Interactive graphic showing changes in housing inventory in the past two years. It has some useful and novel features that make exploring the 18 different cities and 3 different regions easier over the past 20 months.

Here's one of the more interesting charts that I created in just a few minutes of exploration.


For the six cities shown (Miami, Orlando, Chicago, Las Vegas, Los Angeles and Phoenix) the upward trends since October 2005 are plain to see.

Try it out yourself and see what you can discover.

Here are my thoughts on the pluses and minuses of these interactive chart features

On the plus side

1. A single click selects a new factor to add to the mix of factors already selected for the chart

2. When adding a new factor into the mix, it highlights that new factor on the chart and reduces the intensity of the other factors on the chart until you move the mouse over the chart again when all factors selected come into full view. This helps you lock in on the colors for the new factor before they become blended with the other factors.

3. When you move the mouse over the check box for a factor that has already been selected, that factor is highlighted against the other factors currently selected with a little pop up text box that tells you the current inventory value exactly.

4. A single click as all that's required to de-select a factor.

5. A single click for one of the three areas (East, Central, West) selects all the factors for that area. And once a whole area has been selected, a single click de-selects all factors currently checked.

6. All of the above pluses add to ease of use and time saving when exploring this data set for the most interesting and telling patterns.

On the minus side

A. Way too short a time range. To make full sense of these trends and put the recent behavior in perspective needs at least 5 years and preferably 10 to 25 years of history.

B. Some major cities that are in the top 10 in population are missing - New York, Philadelphia, and San Antonio.

C. No way to adjust Y axis scaling. This is a serious drawback. The scale runs from zero to 110 thousand which is fine for viewing the trend for Los Angeles which has a range between 45, 000 and 103,000, but it makes it difficult to grasp the trends for such cities as Minneapolis which varies from 25,000 to 31,000 or Baltimore which ranges from 5,000 to 10,000. Both of these cities look flat line during this period even though when you examine them closely they really aren't. Y axis scaling options such as the possibility of calculating the Min-Max scaling for the factors charted would help bring the trends for all cities into clear view.

D. No available view of the data using percentage change from a baseline value for determining the Y axis value. Such a normalizing option would simplify comparisons between cities.

E. No option for showing aggregate results for a region or for stacking the factors selected.

F. If you wish to look at each factor separately, it takes two clicks. One to de-select the previous factor, and one to select the new factor.

G. No option for smoothing with features such as moving averages

H. Missing trend data for other related factors for each city such as

• Inventory breakdown by New and Existing housing
  
• Average number of months houses have been on the market (total, new, existing)
• Median selling price in that market (total, new, existing)
• Rate of sales per month in that market (total, new, existing)
• Number of months of inventory at current sales rate (total, new, existing)

I. Missing option for downloading the underlying data set thereby enabling further analysis.

Hat tip to Barry Ritholtz at The Big Picture

Consolidating the Iraq Trend Charts from Multiple Sources: A step toward ready-viewability

In the past few days, we've posted a total of 21 charts showing trends that matter on the ground in Iraq. These were culled and selected from 4 separate sources and posted in 4 separate posts. You can scroll down the January 2007 posts from January 17th back to January 13th and find all 21 of these charts in relatively close proximity to each other. Our theory is that by bringing them all to one relatively compact place, we make it easier for those who are interested in learning more about what is happening to have access to the combined analysis and reporting talent from the four sources.

What can we do next? We think this approach makes it easier, but it still is not easy. Due to the current limitations of this blog, the graphs that appear in the blog itself are relatively small in size and to get a full grasp of the message of each trend it is necessary to click on each trend graph to get a full size image. This is pretty unwieldy and involves a lot of extra back and forth clicks to navigate to a good sized view of each trend.

Here's a possible approach to make this a bit easier and less time consuming and require far fewer clicks and allow much better navigation back and forth between the different trend charts. What we've done is to take all 21 trend graphs to create a single down-loadable PDF document that will let you easily view all trends up to the full size your screen while navigating back and forth to the chart you want using the full navigational capabilities of Adobe Acrobat (e.g. page down, page up).

Here's the link - Combine-Iraq-Trends Please let us know what you think of this step towards making these important charts rank higher on a ready-viewability scale.

Did you find the navigation easier?
Did having easy access to all trends in full size improve understanding for you?
What other suggestions do you have to make this even easier?

Download Readily Reusable File Example

Following up our posts from yesterday. It was our intention to make it easy for you to download a readily reusable trend data file that you could try out with the TLViz (TimeLine Visualizer) software or read into your favorite tool such as Microsoft Excel.

Yesterday's method was too complex, took too many keystrokes and sometimes ran afoul of overly smart browser software that changed the format of the file upon downloading.

We now have arranged a workable method that uses a minimum of keystrokes and that preserves the file in its original format so that it will continue to work with TLViz.

Right click on the URL below and save the results to your desktop or designated folder.
http://trendsthatmatter.com/nbu/t4-data/rr-example.csv

Alternatively, you can open the CSV text file in your browser and then select File, Save as to save it to your desktop but the right click method takes fewer keystrokes.

Have fun trying out TLViz. We'll be posting more about this tool and why we think it represents an important demonstration of the potential of readily reusable trend data combined with timeline collaboration methods.