@TechReport{iza:izadps:dp8874,
            	author={New, Sonja C. de and Schurer, Stefanie and Leung, Felix},
            	title={Testing the Validity of Item Non-Response as a Proxy for Cognitive and Non-Cognitive Skills},
            	year={2015},
	month={Feb},
            	institution={Institute of Labor Economics (IZA)},
            	address={Bonn},
            	type={IZA Discussion Paper},
            	number={8874},
            	url={https://www.iza.org/index.php/publications/dp8874},
	abstract={Cognitive and non-cognitive skills are important determinants of labor market outcomes, but are often unobserved. We propose a proxy for these skills derived from item non-response information and a procedure to test its validity. Exploiting a unique data-collection feature of an Australian survey, we find that fraction answered on a self-completion questionnaire fulfils all necessary requirements to be a valid proxy for cognitive skills and outperforms alternative proxies derived from paradata. Fraction answered captures a third of the effect of cognitive ability on wages and education. We provide a simple solution to reduce omitted-variable biases by up to 11%.},
	keywords={paradata;item non-response;proxy-variable approach;cognitive ability;non-cognitive skills;wages;education},
            }