ALT Screenshot of the paper's title page from the American Economic Review (2026, Vol. 116, No. 4). Title: "Negative Control Falsification Tests for Instrumental Variable Designs" by Oren Danieli, Daniel Nevo, Itai Walk, Bar Weinstein, and Dan Zeltzer. The abstract states that IV designs are typically tested using two types of falsification tests, characterized as conditional independence tests between negative control variables and the IV or outcome. The paper describes conditions these proxies must satisfy, shows these tests examine not only independence and the exclusion restriction but also functional form assumptions, and reveals that conventional applications may flag problems even in valid IV designs.