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    "story_id": "mp-2026-07-27-013",
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    "headline": "The Birth-Order Gap May Begin With Germs",
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    "dek": "Danish registry data link early respiratory illness in younger siblings to later health, education and earnings differences.",
    "summary": "Danish registry data link early respiratory illness in younger siblings to later health, education and earnings differences.",
    "body_text": "Northwestern University researchers used Danish records covering first- and second-born siblings from 1981 through 2017. Younger siblings were two to three times more likely to be hospitalized for respiratory illness in their first months, and controlling for that exposure cut the estimated later-born earnings penalty roughly in half. The analysis also linked early illness with chronic respiratory and mental-health outcomes. Registry evidence supports a biological pathway but cannot guarantee the same effect size in other health systems.",
    "why_it_matters": "Danish registry data link early respiratory illness in younger siblings to later health, education and earnings differences.",
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      "Registry evidence supports a biological pathway but cannot guarantee the same effect size in other health systems."
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    "first_published_at": "2026-07-27T09:00:00.000-04:00",
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        "qualification": "Registry evidence supports a biological pathway but cannot guarantee the same effect size in other health systems."
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    "tags": [
      "respiratory illness",
      "birth order",
      "earnings",
      "Denmark"
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      "source_id": "source-2026-07-27-013",
      "title": "Northwestern University via Medical Xpress: Respiratory illness and birth order",
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    "title": "The Birth-Order Gap May Begin With Germs",
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