Roughly a quarter of Americans and around two-thirds of Germans say they believe zodiac signs have at least some connection to personality. Horoscope columns routinely dispense career advice based on birth dates, and a growing share of young adults check astrological compatibility before dates or job decisions. But do the signs actually shape real-world outcomes like the size of a person’s paycheck?
That is the question Matthias Collischon and Florian Zimmermann of the Institute for Employment Research in Nuremberg set out to answer in a paper published in Kyklos. Using administrative records covering more than 11 million observations from about 1 million German workers, they tested whether Western zodiac signs, the familiar sun signs from Aries to Pisces, are linked to wages, education, or managerial rank. Their answer, after a battery of tests: no.
Why economists care about horoscopes
The premise sounds silly, but there’s a serious reason to look. Prior work has shown that superstitious beliefs can move real economic behavior. Studies on Chinese zodiac signs, for instance, have found that people born in the year of the Dragon go on to earn higher wages and get more education, apparently because parents and children act on the widespread belief that Dragons are destined for success. That’s known as a self-fulfilling prophecy: astrology doesn’t have to be true for it to shape outcomes, as long as enough people behave as if it is.
Western astrology could work the same way in principle. Personality traits like extraversion and conscientiousness are known to be associated with higher earnings. If believers absorb the traits their horoscope assigns them, or if employers treat them differently based on their sign, wages could line up with astrological categories even though the stars themselves do nothing.
Collischon and Zimmermann built their hypotheses from standard astrological framework. Sun signs are grouped by “energy” (masculine or feminine), “modality” (cardinal, fixed, or mutable), and “element” (fire, earth, air, or water). Each grouping is supposed to map onto personality traits. Masculine signs are described as extroverted and assertive; feminine signs as introverted and receptive. Fire and earth signs are cast as active or hardworking; water signs as sensitive and emotional. Based on how those traits relate to earnings in the labor economics literature, the researchers predicted that masculine, cardinal, fixed, fire, earth, and air signs should out-earn their opposites, if astrology has any bite.
The data and the method
The researchers drew on the Sample of Integrated Labour Market Biographies, a 2% random sample of German workers covered by social security. After merging in exact birth dates and restricting the sample to full-time workers aged 18 to 65 between 1993 and 2021, they had 11.7 million yearly observations from just under 1.1 million individuals. The main outcome was daily gross wage in inflation-adjusted euros, drawn from administrative records rather than surveys, which cuts out the misreporting that plagues self-reported income data.
A first look at the raw averages seemed to hand astrology a small win. Capricorns, born from mid-December to mid-January, earned slightly less than people born under other signs, and the gaps were statistically significant. Taken at face value, that might suggest the stars really do matter.
But the authors point out a well-documented complication: babies are not born uniformly throughout the year, and the mothers who give birth in different seasons differ systematically. Research has shown that winter births are more common among younger, less-educated mothers, while spring births skew toward more educated ones. Since parental background shapes children’s later wages, any raw wage gap between signs could just be picking up who tends to give birth when.
To get around this, Collischon and Zimmermann used a regression discontinuity design. Instead of comparing all Capricorns to all Sagittarians, they compared only people born within seven days on either side of the date a sign changes. Someone born on December 15 (late Sagittarius) and someone born on December 28 (early Capricorn) come from essentially the same pool of parents and pregnancies. If zodiac signs really do shape wages through personality, wages should jump at each cutoff date. If the raw pattern was just seasonal selection, the jump should disappear.
The jumps didn’t materialize
Across every test the researchers ran, the discontinuities were essentially zero. Comparing masculine to feminine energy signs, the largest wage gap they could find was 18 euro cents against an average daily wage of about 110 euros. The share of wage variation explained by a sign’s energy came in below 0.005%. The same story held for modality (cardinal, fixed, mutable) and for element (fire, earth, air, water). None of the categories predicted by astrological theory produced a detectable wage bump.
The authors then examined each of the 12 signs individually, reasoning that a sign like Aquarius, which combines several traits predicted to boost wages, should show the strongest effect if any signal exists. It didn’t. They also checked whether zodiac signs predicted the odds of holding a managerial job or earning a university degree. Again, nothing.
With more than 11 million observations, the study has enough statistical power to detect very small effects. As the researchers put it, the zero results are unlikely to be an artifact of a small sample. They interpret this as evidence that, whatever Germans tell pollsters about believing in astrology, those beliefs don’t translate into measurable career outcomes.
Why Germany differs from China
The finding sits alongside a growing set of studies on Chinese zodiac signs that do find real effects. Fisman and colleagues have documented how “zodiac year” beliefs alter risk-taking behavior in China, and Zimmermann’s own earlier work found that immigrants from Chinese societies living in Germany who were born under the Dragon sign earn more and get more schooling than their non-Dragon counterparts, while the same pattern doesn’t appear for native Germans born in Dragon years.
Collischon and Zimmermann suggest the difference comes down to intensity of belief. Chinese astrology is deeply woven into decisions about when to have children, how to name them, and how to plan careers. Western astrology, despite its recent popularity in apps and social media, appears not to reshape behavior in the same concentrated way. Believing that Leos are natural leaders, apparently, is not the same as acting on it.
Caveats
The authors are upfront about the limits of their work. Their data doesn’t tell them which individuals personally believe in astrology, so they can’t rule out that committed believers show effects that are washed out by the majority who don’t. They also can’t examine outcomes beyond the labor market. Fertility timing, relationship choices, or consumer decisions might still be shaped by astrological beliefs even if wages aren’t.
The researchers also note that their design captures the effect of being on one side or the other of a sign’s cutoff date, not the full lifelong experience of identifying with a particular sign. Someone born on March 25 is an Aries in their data, and their identity as an Aries is compared to someone born a week earlier as a Pisces. If astrological effects operate only for people who strongly self-identify with their sign and are exposed to it throughout life, the design might miss them, though the sheer size of the sample makes detectable population-level effects hard to hide.
