Transportation Secretary Elaine Chao reportedly failed to cash out her stock options in a large supplier of road-building materials, despite her promise to do so in an ethical agreement that she signed before becoming head of the Department of Transportation (DOT).

Before becoming the leader of the DOT, Chao served on the board of Vulcan Materials, an Alabama-based supplier of various construction substances such as concrete, asphalt, crushed stone, sand, and gravel. She was paid $110,000 and given $151,000 worth of company stock. As part of the ethics agreement that she was required to sign before becoming head of the DOT, Chao stated that she would take “a cash payout for all of my vested deferred stock units” from Vulcan, thereby removing any connection to the company’s wellbeing.

In a recent financial disclosure from Chao’s husband, Senate Majority Leader Mitch McConnell (R-Kentucky), it was revealed that the transportation secretary had not done as she had promised, and instead continued to hold between $250,000 and $500,000 worth of stock in Vulcan.

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While Chao’s clear break from the terms of a binding ethics agreement has concerned ethics watchdogs, many GOP members have attempted to defend her, stating that Chao complied with other measures to distance herself from Vulcan. A DOT official told the public that since the secretary continued to recuse herself from decisions that would affect her former employer, she was still in agreement with the ethics code, and all that had changed is that the form of her payout was in stocks, not cash.

This little change is not so little, however, as stocks can change in value whereas cash cannot (other than inflation, of course). While Chao may not be directly funneling money and projects to a company she has a vested interest in, analysts agree that other actions taken by the DOT can still have a considerable effect on Vulcan’s wellbeing. For example, since the company makes road materials, any infrastructure project conducted by the Department of Transportation could result in a contractor buying materials from Vulcan, thereby increasing its profit and its stock value. Even if Chao truly does not stand to benefit from her stock options, it still begs the question of why she would directly contradict an ethics agreement.