The slogan names the destination and erases the route. The data on what actually produces engaged, durable, well-paid work inverts the direction of causation the slogan assumes.
1. The claim as it is usually told
Do what you love and the money follows. The phrasing travels as a piece of folk Confucianism and as a piece of modern career advice; the two are usually conflated. The version the slogan actually describes: passion precedes the work, passion is identifiable before the work begins, and the labour market will pay the worker who has located the passion a premium because of it. The slogan treats passion as a cause, work as the consequence, and money as the trailing indicator of the cause. The arrangement is tidy. It is also the opposite of what the academic literature in this area finds.
2. Where it originated as far as can be established
The phrase is most often misattributed to Confucius ("Choose a job you love, and you will never have to work a day in your life"). The closest analogue in the Analects is a passage on the governance of virtue, not on careers; the precise wording does not appear in any standard translation of the Confucian corpus that I have located. The modern version appears in self-improvement and career-coaching literature from the late 1990s onward, in roughly the form it still circulates in. The slogan predates the popular academic literature that contradicts it; the academic literature came later and has not displaced the slogan.
3. What it left out
The largest omission is the direction of causation. The research most directly relevant to the claim is summarised in Cal Newport's So Good They Can't Ignore You (2012), which reviews evidence that passion is more often the result of developing rare and valuable skills than the cause of doing so. The adjacent academic literature — including work by Amy Wrzesniewski on "job crafting," by Angela Duckworth on grit, and by Daniel Pink on autonomy, mastery, and purpose — converges on the same direction of causation: passion typically follows competence, not the other way around. The slogan inverts this. The second omission is that the labour market does not, in general, pay a premium for enthusiasm; it pays a premium for scarcity of skill. The worker's wage is the price of the rare skill, not the cost of the felt enthusiasm. The third omission is that the assumption "I know my passion" is a strong one — and that the people who do not know their passion, who are the majority, are left without a slogan and without a plan.
4. The counter-example
The most engaged workers in repeated studies are not, by majority, in the field they identified as their passion at age eighteen. Many entered adjacent fields by accident, developed rare skills in those fields, and grew into engagement. The exemplars named by the slogan's boosters are themselves the counter-example: the founders and operators the slogan is most often deployed to inspire entered the work that made them engaged through a series of contingent, often unglamorous steps that did not begin with passion. The slogan's destination is real. The slogan's claim about the route is not.
5. What the honest version would be
Develop rare and valuable skills in a field you can stand to work in. Passion, if it arrives, will arrive as a result. Three clauses; less slogan-ready; better supported by the evidence. The first clause is the labour-market claim. The second is the rate-of-exposure claim — you have to stay in the work long enough for the rare skill to compound. The third is the humility claim — the destination is real, the route is not pre-known. The slogan collapses three claims into one. The honest version restores them.