Cognitive Consequences of Iodine Deficiency in Adolescence: Evidence from Salt Iodization in Denmark

Benjamin Ly Serena's research to be published in The Scandinavian Journal of Economics

Over the past three decades, many countries have introduced iodized salt policies to eradicate iodine deficiency.

Iodine deficiency in utero is detrimental to cognitive ability, but little is known about the consequences of iodine deficiencies after birth. This paper examines the impact of iodine deficiency in adolescence on school performance.

Benjamin exploits the introduction of iodized salt in Denmark during 1998-2001 as a natural experiment.

Combining administrative records on high school grades over a thirty-year period with geographic variation in initial iodine deficiency, he finds that salt iodization increases the GPA of students by 6-9 percent of a standard deviation.