Numbeo: Aggregating User Generated Data

I (and apparently about 100 other journalists and outlets) received an e-mail from Mladen Adamovic introducing his new offering Numbeo. He’s an ex-Google employee and notes that in his communication: “How expensive is your city? Former Google employee makes an analyzing software.” It’s unclear if this is a hobby site or a commercial effort, but the terms of use are wide open, though data use requires attribution. There’s also a big warning that the data may not be accurate and hasn’t been reviewed by humans. Work planned for this summer aims to identify “incorrect data.”

The site, per his note to the press (available on site’s blog), offers up indexed user contributed data about locations worldwide.

Numbeo allows visitors to share, calculate and compare information about cost of living and properties. It crunches numbers and extract useful and interesting information. The software at Numbeo allows visitors to add and compare indexes for cost of living and residential properties. Visitors can share their local information about restaurant prices, groceries, transportation, utilities, rents, salaries and price of residential properties. Numbeo allows visitors to compare this information with derivated indexes such as consumer price index, domestic purchasing power and others. The correlation of cost of living and residential properties is observable. People who analyze state of residential properties look at information like house price to income ratios, loan affordability index, price to rent ratios, gross rental yields. GDP growth rate and population growth rate influences frequently the increase in price of properties in a particular country over time.

What makes the site different from others?

Comparing to other free Internet software worldwide for cost of living and property investment analysis, our software is the best. It is best because all data are available public, it automatically calculates indexes from user contributed data, visitors can compare all data and we cover the whole world. During the test launch in late May 2009, silent to media, I informed friends mostly through Facebook to collect some data to get the ball rolling. At the moment of writing this message Numbeo have information for 233 cities worldwide in the database and it’s growing fast.

There’s nothing spatial about the site, just pick lists of countries and cities with standard stats in US$ and metric measures for each one. There’s a simple tool to compare one location to another for “cost of living” or “property investment.” I’m impressed the site already has data for some many cities all contributed by users to the just launched site! I would have thought that would require some “seeding.” There were a few things I’d like to see down the road to make the site more useful:

- I’d like to know from how many contributions each stat is derived. That is, he need to report “n=” as my stats professor grilled into us!
- It’d also be useful to know how old the range of source data may for a stat; these numbers vary quite a bit over months and years, so averaging two years old data with one day old data could produce unexpected results.
- “all data are available public” - I’m not sure if the intent to make each raw data set publicly available for others to download and use, but that’d be nice for say, making maps. Alternatively an API might be helpful.
- What is the plan to gather data? Keep it up to date? Cover the planet?