There's a spike in Bitcoin activity around the time foreign aid money goes out

If bitcoin were being used as intended, as a currency, would that not also produce this effect?

"Within the crypto ecosystem, mixers gain relative to both payment processors and ordinary exchanges after disbursement, isolating increased demand for privacy rather than a broad post-aid expansion in crypto activity."

given the technology bieng used, with the complete data sets availible to government and banking officials, it is trivial to (never) determine precise timing,(locations,etc) and amounts, which are very likely going to be almost sycronous, and of exact amounts, that in many cases will perform an almost perfect rebound manouver.

See also the 2nd reaction on the [What-Used-To-Be-Twitter] webpage.

"anyone who follows development finance closely or has worked in the sector knows that the main challenge is getting the funds to reach their destination and avoid getting diverted by corrupt officials"

Even if the money is used completely legitimately it will be exchanged for goods and services thus ending up in someone's pocket. Someone who may want to buy Bitcoin.

lmao