The Balance Sheet Records What the Smoke Does

This chapter follows the distant-smoke pathway into household credit accounts. The focus is not simply whether borrowers eventually miss a payment, but how spending, repayment, balances, and delinquency change over time after wildfire-attributable pollution. Reading those measures together lets us see a financial shock developing without mistaking one account statistic for a complete measure of household welfare.

Delinquency is the visible end of a longer chain

The Philadelphia Fed study compares households outside the burn zone that experienced heavier and lighter wildfire-related pollution. In the main Camp Fire analysis, the sample is five to 30 miles from the perimeter, so the households are close enough to receive substantial smoke but are not being treated as direct property-damage cases. The paper reports that heavier pollution raises several forms of credit delinquency. In the ordinary pollution-change estimates, credit-card delinquency rises by 2.1 percentage points and personal-loan delinquency by 3.5 percentage points. In the instrumental-variable estimates, the corresponding increases are 2.8 and 3.7 percentage points, with a smaller but statistically significant mortgage effect as well.

Those numbers have to be read with their denominator and unit attached. A percentage-point increase changes the rate of delinquency relative to the study's comparison group; it is not the same as saying that delinquency increased by 2.1 percent, and it does not mean that 2.1 percent of every smoke-exposed household became delinquent. The estimates describe a difference between groups under a defined pollution contrast. The study's design makes the contrast more informative than a simple cross-sectional correlation, but it still does not imply that every household responds in the same way or that the exact coefficients will recur after another fire.

The difference between the two sets of estimates is also informative. The ordinary specification uses a measured change in pollution, while the instrumental-variable approach uses a source of variation intended to isolate wildfire-attributable pollution more sharply. The estimates do not need to match exactly to tell the same directional story. What matters here is that both approaches report higher delinquency for credit cards and personal loans after heavier wildfire-related pollution. The remaining uncertainty concerns magnitude, applicability, and the assumptions needed to interpret the instrument—not whether a single rounded number should be treated as the one true effect.

Persistence is another part of the result. The paper reports that the credit-card delinquency effect remains elevated for as long as two years after the Camp Fire, while the personal-loan effect is elevated for a shorter period and tends to dissipate. A smoke event can therefore leave a financial trace after the most visible pollution has passed. The event may be brief, but the account does not reset automatically when air quality improves. A missed payment can add fees, damage a credit history, reduce access to future borrowing, or force a household to use one account to keep another current. The paper measures delinquency outcomes; those secondary consequences are reasonable financial implications, but they are not separately estimated in the cited result.

Persistence also changes the meaning of exposure.