🤖 AI Summary
スマートフォンが不妊率の低下に貢献している可能性があるという最近の2つの研究があります。一つは5月に発表され、タイトルが「デジタルエraにおけるteenagersの妊娠減少」という研究で、もう一つは最近発表され、「iPhoneは避妊法か?AT&Tの2007-2011年キャリア独占から因果証拠」という研究です。これらの研究によると、スマートフォンはteenagersがリアルタイムの社交時間や性的な頻度を減らし、非計画的な妊娠の場面を減少させることで不妊率を低下させる可能性があると主張しています。
特に第二の研究では、アメリカ全土の総 fertility rate が2007年から22%減少したことを指摘しており、この傾向は経済状況や避妊方法など一般的に引用される要因で説明し難いものであるという点も強調しています。研究者たちはiPhoneの普及率をAT&Tの携帯通信網の広がりから評価し、「iPhoneによる出産数の減少は15-19歳では4.5%から8.0%、20-24歳では3.2%から6.6%であり、統計的に有意な減少傾向がある」と結論づけています。
これらの研究は、リアルタイムの社交時間や性的頻度の減少が非計画的な妊娠を減らし、結果として不妊率を低下させる可能性があることを示唆しています。
Two recent studies argue that smartphones may have contributed to falling birthrates by reducing in-person social interaction, sexual frequency, and other conditions tied to unintended pregnancies. "One of the studies published in May is called 'The Collapse of Teen Fertility in the Digital Era' and the other, published just Monday, is titled 'Is the iPhone Birth Control? Causal Evidence from AT&T's 2007-2011 Carrier Monopoly,'" reports KTLA. "Both were chronicled in a New York Times piece by political writer Sabrina Tavernise on Monday." Slashdot reader sabbede submitted the story. From the report: The one from May, authored by two University of Cincinnati professors, posits that teen fertility "collapsed globally" starting around 2007 -- the same year the first iPhone was released. "Smart phones changed how teens spend time with each other ... this change in turn drove the collapse in teen fertility," the study's abstract reads. "Once enough teens are on the phone, being on the phone is where the peer network is; in-person time falls sharply, and with it the unstructured contact in which most unintended teen conceptions occur." The study claimed that countries "across the income and policy spectrum" were affected by the teen fertility drop, and that researchers used data from multiple countries, including the U.S., England and Wales, to rule out "country-specific contraceptive access and welfare reform stories." "This model predicts that the shift towards the phone-mediated equilibrium affects multiple aspects of teen behavior," the abstract continues, concluding that "the same instrument that produces a collapse in teen fertility produces a surge in teen suicides."
The study published on Monday looks more closely at the United States, explaining that nationwide general fertility rates have fallen 22% since 2007. "[This is] a sustained decline not readily explained by economic conditions, contraceptive use, housing or childcare costs, or other commonly cited factors," the National Bureau of Economic Researchers study states. "We assess the potential role of a different shock: the diffusion of the smartphone." As mentioned before, the first iPhone was rolled out in 2007, and this study makes use of that timeframe as "a natural experiment" by using data from 2007 through 2011, when iPhones were only sold on AT&T. "From June 2007 through February 2011, the device was sold only on AT&T, allowing us to identify its effect from variation in AT&T's mobile broadband coverage," the study says. "Entropy-balanced Poisson and synthetic difference-in-differences event studies imply that access to the iPhone reduced births by 4.5-8.0% at ages 15-19 and 3.2-6.6% at ages 20-24, with statistically significant but smaller declines among older cohorts. Placebo analyses applied to Verizon and Sprint's pre-2011 coverage footprint are null.
Taken together, these cohort effects imply that the diffusion of the iPhone deepened the decline in births among women under 30 while suppressing the rise in births among older women." "Overall, the diffusion of the iPhone explains 33-52% of the decline in the general fertility rate among women aged 15-44," researchers continued. "National-survey evidence on time use and sexual behavior is consistent with the iPhone reducing in-person interactions, increasing pornography use and reducing sexual frequency."
Read more of this story at Slashdot.