A myriad of recent studies in developed countries find a sizeable and significant negative relation between higher birth order and adult outcomes such as IQ, educational attainment, and wages. This effect seems to be driven by worsening quality in investments by parents of latter-born children rather than differences in endowments at birth. However, to date, little is known about whether social and economic changes might impact this source of within-family inequality. In order to answer this question, we use a unique long historical span of linked administrative data with occupational information from a sample of individuals born from mid-19th century to mid-20th century in The Netherlands. Over this period, the Netherlands experienced high levels of economic growth and development, with a reduction in the share of population working in the agricultural sector or a sharp decrease in fertility among other changes. Consistent with previous literature in developed countries, we find an average negative birth order effect that does not experience significant changes over time. We find that this effect is mostly driven by first-borns and that the more male siblings are born earlier the more negative the birth order effect, which indicates a stronger competition among resources within male siblings. Interestingly, we do not find any evidence supporting that changes in economic conditions go hand by hand with changes in the magnitude nor size of the birth order effect.