I think that the idea that data lies is false, and that such a notion is commonly held a sign of lazy intellect. You can present data in different ways to focus on different aspects of a system. And you can make faulty assumptions based on data you look at.
It is true someone can just provide false data, that is an issue you have to consider when drawing conclusions from data. But often people just don’t think about what the data is really saying. Most often when people say data lies they just were misled because they didn’t think about what the data actually showed. When you examine data provided by someone else you need to make sure you understand what it is actually saying and if they are trying to support their position you may be wise to be clear they are not misleading you with their presentation of the data.
Here is some data from Greg Mankiw’s Blog. He wants to make his point that the USA is taxed more on par with Europe than some believe because he want to reduce current taxes. So he shows that while taxes as a percent of economic activity is low in the USA taxes per person is comparable to Europe.
France .461 x 33,744 = $15,556
Germany .406 x 34,219 = $13,893
UK .390 x 35,165 = $13,714
US .282 x 46,443 = $13,097
Canada .334 x 38,290 = $12,789
Italy .426 x 29,290 = $12,478
Spain .373 x 29,527 = $11,014
Japan .274 x 32,817 = $8,992
The USA is the 2nd lowest for percent of GDP taxes 28.2% v 27.4% for Japan. But in taxes per person toward the middle of the pack. France which has 46% taxes/GDP totals $15,556 in tax per person compared to $13,097 for the USA. Both measures of taxes are useful to know, in my opinion. Neither lies. Both have merit in providing a understanding of the system (the economies of countries).
Related: Fooled by Randomness – Simpson’s Paradox – Mistakes in Experimental Design and Interpretation – Government Debt as Percentage of GDP 1990-2008 by Country – Communicating with the Visual Display of Data – Illusion of Explanatory Depth