Primary Submission Category: Economic development
Male twin live births following a universal basic income program in Alaska: A population-level test of selection in utero
Authors: Parvati Singh Nicholas Mark Kiara Douds Sarah Cowan
Presenting Author: Parvati Singh*
Economic certainty and optimism about the future may underlie birth patterns in a population. In the US, the Alaska Permanent Fund Dividend (PFD), disbursed to all persons residing in the state of Alaska, exhibits a sizeable fertility response. PFD disbursements began in 1982 following operationalization of the Trans-Alaska Oil Pipeline System, with annual payments ranging from $600 to $2500, and continues to the present day. Increased economic certainty from the PFD may increase optimism about the future, with implications for birth cohort composition and fitness.
The theory of selection in utero posits that unfavorable external circumstances increase sex-specific spontaneous abortions (or miscarriages) during pregnancy, with higher likelihood of male fetal loss relative to female. As a corollary, periods of social prosperity may precede an increase in male live births owing to better survival and reproductive success during favorable external circumstances. Male twin gestations appear particularly sensitive to selection in utero and occupy the left tail of the gestational frailty distribution. Multiple studies report changes in the patterning and volume of male twin live births as a strong marker of external circumstances, including ambient stress and collective optimism.
We examine whether the odds of male twin live births increased within 3-6 months (consistent with prior research) following month and magnitude of amounts disbursed through the Alaska PFD using Alaska vital statistics birth data from 1980 to 2019. We use Autoregressive Integrated Moving Average (ARIMA) time-series methods to account for autocorrelations in births. Results from ARIMA analyses indicate an increase in the odds of male twin live births 3 months following $1000 increments in PFD receipt (coefficient = 0.0016, p < 0.05). These results remain consistent upon outlier adjustment. Our finding supports reduced selection in utero following increase in income receipt from the Alaska PFD.