Joseph Richardson @JosephLabour

PhD Economics student @LancasterUni. Interested in labour, education, and health. sites.google.com/view/joseph-ri… United Kingdom Joined January 2016

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Joseph Richardson @JosephLabour

2 weeks ago

@RenaudFoucart You could probably also describe aspects of TikTok in that way, but it's much more contained onto one site than the old person slop.

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Joseph Richardson @JosephLabour

2 weeks ago

@Caitlin_K_Myers I agree that there is less of a change in 2008 in the Poisson, but I'd be concerned about pre-trends instead there. I think every age group with a statistically significant post effect also would have a jointly statistically significant pre-trend as well.

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Joseph Richardson @JosephLabour

2 weeks ago

@Caitlin_K_Myers I'd say that while 2008 seems very big for 15-19 year olds (and maybe too significant to be noise), but for everyone given the very low ownership (maybe 1 or 2%) at the time. Across synth event studies, the 2008 effects seems to be at least 50% of the effect in later years.

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Joseph Richardson @JosephLabour

3 weeks ago

@idrechs @Caitlin_K_Myers I also thought that!

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Joseph Richardson @JosephLabour

3 weeks ago

@Caitlin_K_Myers The one explanation I can think of is maybe 2008 hit very large metros differently? The placebos without AT&T will places like Lubbock rather than NYC or Chicago.

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Joseph Richardson @JosephLabour

3 weeks ago

@Caitlin_K_Myers I like the way you've responded here, but there is still something that doesn't quite add up for me : how is the synth DiD picking up a very statistically significant 5% fertility drop in 2008 when about 1% of the US population has an iPhone in the relevant conception period?

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Joseph Richardson @JosephLabour

3 weeks ago

I'm pleased to announce that I will be joining @uniofwarwick in August as a Teaching Fellow in Economics. I look forward to meeting everyone there.

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Joseph Richardson @JosephLabour

3 weeks ago

@MosheEcon Although I will grant the statement of their questions is potentially misleading. They're focusing on point estimates and completely ignoring inference when it doesn't sound like they are, although that is common in the sensitivity analysis literature.

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Joseph Richardson @JosephLabour

3 weeks ago

@MosheEcon Type M error is where your estimator is underpowered, so all statistically significant results are overestimates of the true effect. Can happen when no omitted variables bias is present at all.

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Joseph Richardson @JosephLabour

3 weeks ago

@RenaudFoucart At least I'm not too concerned about a 16 and pregnant confound. But that kind of thing is be a general difficulty for this kind of identification strategy. tandfonline.com/doi/full/10.10…

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Joseph Richardson @JosephLabour

3 weeks ago

Are we actually confident that the iPhone launch massively decreased teen births specifically in 2008? Most people (>95%?) didn't have iphones and I doubt many were buying such a luxury for teenagers. My money is on something to do with the great recession.

Jeremy Neufeld @JeremyLNeufeld

3 weeks ago

More evidence it's the phones: @Caitlin_K_Myers and Ezekiel Hooper find "the diffusion of the iPhone explains 33–52% of the decline in the general fertility rate among women aged 15–44" since 2007. nber.org/papers/w35310

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Joseph Richardson @JosephLabour

3 weeks ago

@lymanstoneky Since they're getting these big effects at times when almost no one had an iPhone and on groups with particularly low ownership, I suspect one of those mysterious reasons is correct. There's also a massive pre-trend in the Poisson event study. x.com/JosephLabour/s…

Joseph Richardson @JosephLabour

3 weeks ago

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Joseph Richardson @JosephLabour

3 weeks ago

@DavidJo30329121 It could include any mixture of things that differentially affected urban and rural areas around that time which wasn't fully controlled for! Since the timing and effect sizes don't seem particularly plausible, that's a problem.

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Joseph Richardson @JosephLabour

3 weeks ago

@YoungEcon There are multipliers and there are multipliers. The big (5%+) effects in the SDiD start in 2008 when maybe 2% of the US population had an iPhone in the relevant conception (late 2007-mid 2008). I wouldn't trust the Poisson because it has obvious pre-trends.

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Joseph Richardson @JosephLabour

3 weeks ago

This is based on the following global iPhone sales numbers. CY2007: ~3.7M CY2008: ~13.7M

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Joseph Richardson @JosephLabour

3 weeks ago

There's a 5% drop in 2008 for teen births when less than 5% of Americans had iPhones in the relevant conception period. I imagine promiscuous teenagers, who typically come from poor families, had far lower ownership rates than 5%.

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Joseph Richardson @JosephLabour

3 weeks ago

I wonder if people react better to text written by an LLM they don't use themselves. Reading writing begins feeling tedious when I see Claudeisms, but I can't spot ChatGPT as easily. An anti-monopoly force in the market?

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Joseph Richardson @JosephLabour

4 weeks ago

@joefrancis505 @FeeloPi @paulkrugman @lugaricano I don't see a tension. Labour market reforms and reductions in regulatory burdens are compatible with universal healthcare and a reasonable safety net (although pension reform is needed). Nordic countries are proof that the rest of the EU is not on the possibilities frontier.

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Dan Neidle @DanNeidle

4 weeks ago

This is a brilliant idea:

quibble @quibbleUK

4 weeks ago

Hello, we are Jonathan and Abigail - unashamed pedants who want to bring this affliction to bear on all things public policy and practice. We believe that details matter, especially in public administration. This is why today we are founding quibble: a campaign to fix the small