Beginning in 1996, the plaintiff-appellants, subsidiaries of the Canadian National Railway Company (to simplify we’ll refer to the subsidiaries as “the railway”), began including stock options in the compensation plans of a number of employees. In this suit against the government, the railway argues that income from the exercise of stock options that a railroad gives its employees is not a form of “money remuneration” to them and is therefore not taxable to the railway as compensation under the Railroad Retirement Tax Act, 26 U.S.C. § 3281(e)(1), which defines “compensation” as “any form of money remuneration paid to an individual for services rendered as an employee to one or more employers.” See also BNSF Railway Co. v. United States, 775 F.3d 743 (5th Cir. 2015).
As explained in Standard Office Building Corp. v. United States, 819 F.2d 1371, 1373 (7th Cir. 1987), “the Railroad Retirement Tax Act, passed in 1937, is to the railroad industry what the Social Security Act is to other industries: the imposition of an employment or payroll tax on both the employer and the employee, with the proceeds used to pay pensions and other benefits .... The Act requires the railroad to pay an excise tax equal to a specified percentage of its employees’ wages, and also to withhold a specified percentage of its employees’ wages as their share of the tax. The railroad retirement tax rates are much higher than the social security tax rates.”
The question presented by this case is whether the excise tax should be levied not only on employees’ wages but also on the value of stock options exercised by employees who, having received the options from their employer, exercise them when the market price exceeds the “strike price” (the price at which the employee has a right to buy the stock) and thus obtain the stock at a favorable price. The Internal Revenue Service answers yes, see 26 C.F.R. § 31.3231(e)-l, and the district court agreed, precipitating this appeal.
The lawyer for the IRS told us at oral argument that anything that has a market value is a “form of money remuneration.” That goes too far; it would impose a tax liability on an employer who bought an employee a birthday cake, even though the employee could do nothing with his cake except eat it or give it away. But if instead he exercises a stock option, he now owns stock, and stock has so well-defined a monetary value in our society that there is no significant economic difference between receiving a $1000 salary bonus and a share or shares of stock having a market value of $1000.
By compensating an employee with stock options rather than cash the employer encourages the employee to work harder for the company, because the better the company does the more valuable its stock *492is. The value of a company’s stock is a function of the company’s profitability, whereas the size of a cash bonus, once it is given, is unaffected by the company’s future business successes or failures. Underscoring the point, we note that the railway’s stock-option plans are performance-based: they can be exercised only if the company achieves specified goals.
As the discussion in the preceding paragraphs implies, the fact that cash and stock are not the same things doesn’t make a stock-option plan any less a “form of money remuneration” than cash. Indeed the railway offers its employees a choice to have an agent exercise an employee’s stock option, sell the shares of stock obtained by that exercise of the option, reserve part of the money received in the sale for taxes and administrative costs, and deposit the balance in the employee’s bank account. An employee who uses this method will thus experience the stock option as a cash deposit.
It’s true that the Railroad Retirement Tax Act, in which the term “money remuneration” appears, dates back to 1935, when the nation was mired in the Great Depression of the 1930s which had driven down the value of corporate stock. Maybe stock then wasn’t a form of money remuneration, but there is no reason to think that the framers and ratifiers of the Act meant money remuneration to be limited to cash even if, as was eventually to happen, stock became its practical equivalent, just as today 100 dimes is the exact monetary equivalent of a $10 bill. A $10 bill is paper; so is a stock certificate that can be sold for $10. The dictionary definition of money may remain constant while the instruments that comprise it change over time: sheep may have once been a form of money; now stock is. The Internal Revenue Code of 1939 is of limited help here; it treats “money” and “stock” as different concepts, but that’s not inconsistent with stock options’ falling within “any form of money remuneration.”
The equivalence of stock to cash is actually signaled in the statutory exception for qualified stock options, explicitly divorced from “money remuneration” by 26 U.S.C. § 3231(e)(12). That exception, by virtue of its narrowness, supports an inference that non-qualified stock options, which are the options at issue in this case, are covered by the term “money remuneration” and are therefore taxable. There are moreover other statutory exceptions for other forms of non-cash employee benefits, and their existence reinforces the inference that non-qualified stock options are “money remuneration” and therefore taxable. See, e.g., § 3231(e)(1) (excluding payments for health insurance or health care and travel expenses); (e)(5) (excluding non-cash employee achievement awards); (e)(6) (excluding educational benefits); (e)(9) (excluding value of meals and lodging provided to employees); and (e)(10) & (11) (excluding contributions for medical and health savings plans).
The government’s position also makes good practical sense by avoiding the creation of a tax incentive that might distort the ways in which employers structure compensation packages for their managers. And finally we are not alone in equating non-qualified stock options to money remuneration in the Railroad Retirement Tax Act. See BNSF Railway Co. v. United States, supra, 775 F.3d at 757; CSX Corp., et al. v. United States, No. 3:15-cv-427-BJD-JRK (M.D. Fla. March 14, 2017).
Affirmed.