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Latest — 22 Aug 2026

Cache-Control for LLMs

Claude Sonnet 5 charges \$2.00 per million fresh input tokens. Writing them into a five-minute cache costs \$2.50, and every read after that costs \$0.20 (see here). So two identical calls cost \$2.70 with caching instead of \$4.00. One reuse pays for the write.

More issues

Reverse Dependency Checks for Empirical Outputs

When you change an R package, CRAN expects you to run reverse dependency checks: build every package that depends on yours and see what breaks. When you fix a bug in a statistical package, it might be worth running the equivalent check against papers. To run the check, you need

Notes from a fan

A few days ago I was looking at Wirecutter's best-fan guide. The Vornado 630 was \$60 on Amazon, \$80 on Walmart, and \$80 on Vornado's own website. A 33% gap on a fan caught my attention. I wondered how common gaps like this were. So

Science: 20 GPs in a single District

One of the quieter successes of post-Independence India is that the gender gap in education has closed. The trajectory is plain in the historical data. In 1951, fewer than three in ten girls were enrolled at the primary level, against six in ten boys; at upper primary, girls were

Ceci N'est Pas un Proxy

Chaturvedi, Das, and Mahajan (2024) argue that female reservation in the 2015 Gram Panchayat elections raised household toilet provision more in villages with a higher Muslim share. At low Muslim share the estimated reservation effect is essentially zero. In villages where Muslims make up about a quarter of the population,

The Ties That Bound

The previous post described a conservative record-linkage pipeline: accept only high-confidence matches, flag ambiguous cases, and leave the rest unmatched. That is the right approach when false matches are more costly than missed ones, but it means the matched subset is selected on ease of matching, and estimates

Join, or Die

Record linkage is the problem of identifying the same entity across two or more tables that lack a shared unique identifier. You have a name, maybe a district, maybe an age, and you need to figure out which row in table A corresponds to which row in table B. When

Recommended Treatment

The effect of a treatment on an outcome depends on three things: the kind of treatment, the kind of person receiving it, and the context in which it is delivered. A ranking change and a button color change work through different mechanisms. A heavy user and a new user will