Field notes from shipping real systems - automation, analytics, and the messy middle of digital transformation.https://joechrisnaldy.com/https://joechrisnaldy.com/blog/calories-in-calories-out-explains-almost-nothing/https://joechrisnaldy.com/blog/calories-in-calories-out-explains-almost-nothing/Ten countries put more than 3,700 calories a day on the shelf per person. Their food supply varies by 5.8 percent. Their adult obesity rates run from 14.1 percent to 40.7 percent. Across 168 countries, calorie supply accounts for 5.7 percent of the variation in obesity. Energy balance is an accounting identity: true in every country, which is exactly why it cannot explain why they differ.Fri, 07 Aug 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-payback-period-assumes-you-are-paying-it-back/https://joechrisnaldy.com/blog/the-payback-period-assumes-you-are-paying-it-back/Divide a degree's median debt by its graduates' median earnings and you get the price of that degree in years of salary. Across 31,941 US programmes the median is 0.59, about seven months. That sum is correct. It is also a price, not a deadline, and it quietly assumes a ten-year repayment schedule that about one federal loan dollar in five is actually on.Wed, 05 Aug 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/a-quarter-of-county-income-is-a-transfer/https://joechrisnaldy.com/blog/a-quarter-of-county-income-is-a-transfer/BEA defines personal income as the income received by, or on behalf of, all persons. Everyone quoting a county income figure says the first half. In the median American county transfers are now 26.2% of personal income, and nearly half of those are medical benefits paid to providers rather than handed to the people they are counted for.Fri, 31 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/labour-laws-still-assume-you-work-saturday/https://joechrisnaldy.com/blog/labour-laws-still-assume-you-work-saturday/Forty hours is five eight-hour days. Forty-eight is six, and in 2012 a third of the countries with a working-hours law still legislated one. The world's labour codes agreed most closely in 1949 and have drifted apart ever since, and the number that standardised turns out not to be the number that sets the outer limit.Thu, 30 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/nobody-quit-nobody-was-unemployed-either/https://joechrisnaldy.com/blog/nobody-quit-nobody-was-unemployed-either/Every month the world reads two numbers and decides how the job market feels. One of them counts people who left a job even when they walked straight into another one. The other counts only people who are still actively looking, so it loses anyone who gives up. Both numbers are real. Neither measures the thing we use it to measure.Wed, 29 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-survey-couldnt-count-indonesias-business-owners/https://joechrisnaldy.com/blog/the-survey-couldnt-count-indonesias-business-owners/Two in five Indonesian workers work for themselves, and there are ten million more of them than a decade ago. The world's best-known entrepreneurship survey records the opposite: a fall of roughly three quarters. It turns out the survey found them. What broke was the step that decides whether a business counts.Wed, 29 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-easiest-promise-to-keep-is-the-one-you-can-count/https://joechrisnaldy.com/blog/the-easiest-promise-to-keep-is-the-one-you-can-count/Indonesia put an education spending share into its constitution, went to court to enforce it, and has met it every year since 2009. The money was budgeted exactly as promised. The reading was not. A percentage is a promise about an input, and it can be kept in full while the thing it was meant to buy stays out of reach.Mon, 27 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-lung-cancer-dataset-that-cant-see-smoking/https://joechrisnaldy.com/blog/the-lung-cancer-dataset-that-cant-see-smoking/The most-downloaded lung-cancer dataset on the internet, run through the obvious analysis, says smoking barely matters for cancer. It is wrong, and the reason it is wrong is a trap every data scientist should be able to see. Smoking causes the large majority of lung cancer, and there is no safe amount.Tue, 21 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-benefit-that-costs-less-than-it-delivers/https://joechrisnaldy.com/blog/the-benefit-that-costs-less-than-it-delivers/A US food program hands families more groceries than taxpayers pay for. The difference is quietly covered by the companies that make infant formula, who compete to be the one brand the program buys. It is one of the more clever pieces of design in the safety net, and almost nobody talks about it.Mon, 20 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/everyone-knows-social-media-is-wrecking-teens/https://joechrisnaldy.com/blog/everyone-knows-social-media-is-wrecking-teens/We have already reached a verdict: social media is wrecking teenagers. It is a bestseller, a Surgeon General warning, a wave of school phone bans. But the evidence under all that certainty is surprisingly thin, and we cannot even measure the thing we are so sure about.Sun, 19 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/what-the-bank-sees/https://joechrisnaldy.com/blog/what-the-bank-sees/You fill in thirty boxes about your life and a lender turns you into one yes-or-no number. This synthetic dataset ships the formula behind its own answers, so for once we can read the rulebook, and it is not weighing the thing you think it is.Wed, 15 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-most-generous-country-isnt-the-happiest/https://joechrisnaldy.com/blog/the-most-generous-country-isnt-the-happiest/No country on earth gives more than Indonesia, and few feel more daily joy, yet it ranks about 80th on the world happiness ladder. That gap is the whole story: how you rate your life and how you feel living it are two different questions, and the famous ranking only measures one of them.Tue, 14 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-score-you-didnt-build/https://joechrisnaldy.com/blog/the-score-you-didnt-build/A popular food dataset ships a 'health score' that literally adds grams of fat to milligrams of calcium. Reverse-engineering it took one line of code. Here is how to tell a number that was measured from a number someone made up, and why it matters for every score you did not build yourself.Tue, 14 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/what-actually-moves-your-mental-health/https://joechrisnaldy.com/blog/what-actually-moves-your-mental-health/If you want to protect your mental health, the data has a clear favorite, and it isn't a sleep app or a gym streak. It's two quieter things: work-life balance and someone to lean on. Here is what happens when you rank the levers honestly, and why it matters for whether you can work at all.Sun, 12 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/everyone-says-substance-everyone-picks-chemistry/https://joechrisnaldy.com/blog/everyone-says-substance-everyone-picks-chemistry/Speed daters rank intelligence at the top of what they want in a partner. Minutes later, they hand out 'yes' on the basis of something else entirely. The list of what we want is mostly a wish; the choosing is the tell, and it turns out to be the same tell for men and women.Sat, 11 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/nobody-builds-a-world-cup-team-at-home-anymore/https://joechrisnaldy.com/blog/nobody-builds-a-world-cup-team-at-home-anymore/Indonesia missed the 2026 World Cup with a squad mostly born in the Netherlands, and half the country argued about whether that team was really theirs. So I counted where every qualifier's players actually work. Four in five play abroad, and Indonesia was not breaking the rules of the modern game; it was finally playing by them.Sat, 11 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-cheapest-degree-abroad-isnt-the-best-deal/https://joechrisnaldy.com/blog/the-cheapest-degree-abroad-isnt-the-best-deal/A master's in the USA costs about thirteen times one in Greece. But sticker price is the wrong ruler. Once you divide the cost by what you would actually earn, the bargain ranking reshuffles, and the cheapest countries stop being the best deals. Mexico looks cheap and is one of the worst.Sat, 11 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/the-gaming-addiction-number-nobody-checked/https://joechrisnaldy.com/blog/the-gaming-addiction-number-nobody-checked/One Indonesian study flags 1.9% of young gamers as at risk of a gaming disorder; another finds 30.8% have already experienced one. A gap that size is not a fact about kids; it is a fact about measurement, and here is how an 'addiction score' gets built.Fri, 10 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/a-model-can-be-86-percent-right-and-useless/https://joechrisnaldy.com/blog/a-model-can-be-86-percent-right-and-useless/On a dataset of 690,000 students, a model that is right 86% of the time is worthless, and a model that is less accurate wins the competition. The reason is a single upstream decision almost nobody argues about: the metric you agree to be judged by.Thu, 09 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/property-isnt-the-hedge-you-think/https://joechrisnaldy.com/blog/property-isnt-the-hedge-you-think/When Russia's currency collapsed in 2014, Moscow apartment prices didn't fall; they rose. That's exactly how property owners lost a third of their wealth in world prices without noticing. A data story about the most dangerous kind of stability.Thu, 09 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/waking-the-sleeping-giant/https://joechrisnaldy.com/blog/waking-the-sleeping-giant/Last fall, I had the honor of moderating a conversation with Pak Gita Wirjawan, former Minister of Trade of Indonesia, at Columbia University. Here is what the discussion taught me about Indonesia's future, and why I believe our generation holds the key.Thu, 09 Jul 2026 00:00:00 GMThttps://joechrisnaldy.com/blog/4-months-into-running/https://joechrisnaldy.com/blog/4-months-into-running/Four months ago, I had never run more than 5 KM. Last week, I ran around Manhattan Island. Here is what running taught me about the power of mindset.Sun, 28 Jun 2026 00:00:00 GMT