Effortless Perfection: Do Chinese Cities Manipulate ‘Blue Skies?’
April 30, 2013 Leave a comment
Effortless Perfection: Do Chinese Cities Manipulate ‘Blue Skies?’
Dalia Ghanem University of California, San Diego (UCSD)
Junjie Zhang University of California, San Diego
April 16, 2013
Abstract:
It is alleged that some Chinese cities manipulate their air pollution data to comply with the air quality standards set by the central government of China. This paper tests this hypothesis by using a unique data set. First, we employ a discontinuity test to detect the cities that reported dubious pollution data around the cutoff for “blue-sky days.” Then, we propose a panel matching approach to identify the conditions under which irregularities may occur. Over the period 2001-2010, 55% of cities reported dubious PM10 pollution levels that led to a discontinuity at the cutoff. Suspicious data reporting tends to occur on days when the potential manipulation is least detectable. Our findings indicate that the official daily air pollution data are not well behaved, which provides suggestive evidence of manipulation.