The basic limitation of longitudinal  burn rate analysis is the exclusions. A trendline requires a consistent rule on exclusions. In reality, during 5 years my exclusion rule would be different from the previous or next 5 years. If we don’t address this limitation, then trendline is meaningless and misleading.

I have been tracking family burn rate for a few years. In 2015-2016 it was above $5k/month, excluding transfers, mortgage or UChicago fees. If excluding IRAS then about $4~5k.

Note: IRAS was up to $700/M, averaged below $500/M, complicated by baby bonus rebates.
Note: transfers to grandma or wife are usually spent on household.

In 2020/21 the average is below $4k/M excluding transfers, IRAS, cigna prem. It’s useful to investigate the improvement, and hopefully strengthen it. Luckily, with financial numbers it’s easy to drill down to uncover the exact reasons. Here’s my high-level explanation.

• ⭝MindChamps .. was $900/M.
• ⭝flights + restaurants .. was once close to $1000/M, nowadays below $300/M. After covid19, this expense will increase.
• ⭜insurance premium .. is  higher nowadays, perhaps by $400/M
• ⭜piano costs ..

— In 2022, our burn rate is likely to inch up to $5k, hurting our Brbr.

In Feb 2022, I told wife about $9k/M but using different exclusion rules:

• + I record about $4k/M as the headline burn rate
• + $1800/M is transferred to wife and usually spent
• + IRAS about $900/M
• + mtg interest cost will be $500/M assuming 1.2% pa interest rate.
• + mtg principal repayment about $2k/M