Data studies
Longer-form pieces that compute results from public-source data rather than summarising someone else’s opinion. Each piece cites its sources and shows the math. Updated when the underlying data changes meaningfully.
The true 30-year cost of a US mortgage at every rate from 3% to 8%
Lifetime interest on a $400k loan computed end-to-end. Where every dollar goes, broken down by rate. The numbers compound interest doesn't show until you ask.
Fifty years of DST changes: a tour of the IANA tzdata history
39 entities changed their DST rules between 1990 and 2024. Why, when, and what it costs downstream when your code doesn't update the database.
Tipping conventions in 50 countries: what's expected, what's offensive, what's optional
Synthesised from consulate guidance, hospitality associations, and traveller forums. The countries where tipping insults the staff, the countries where you'd better leave 20%.
BMI calculator accuracy: where the popular sites diverge (and where they don't)
The formula is one line. Rounding, imperial-conversion factor, and category-band labels still produce small inter-calculator disagreements.
EUR/USD volatility 2020-2024: what 5 years of ECB rates tell you
The euro went from 1.22 USD to below parity and back. A 21% peak-to-trough range. What it costs unhedged businesses and travellers.
US 30-year mortgage rate vs 10-year Treasury: the spread that explains your APR
Mortgage rates track Treasury yields plus a ~1.7 pp average spread. 2022-2023 saw it widen to 2.5-2.9 pp. What's behind it and what it means for refinance timing.
TLS certificate lifetimes: 5 years → 47 days, 2011-2026
Public CT log data shows median TLS cert lifetime dropped from 36 months in 2011 to 90 days today. CA/Browser Forum is pushing to 47 days by 2029. Why automation is now mandatory.
Recipe ingredient density: how 6 reference sources disagree by 30%
King Arthur, ATK, USDA, Joy of Cooking, Bob's Red Mill all give different gram weights for '1 cup of flour'. Side-by-side analysis of the spread and what it means.