Economist. See my MIT webpage to verify that this is me. Evidence-based economics and finance and humor. I do not endorse any cryptocurrency investment.
Joined November 2012
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Jonathan A. Parker retweeted
Denmark is raising its retirement age to 70. French election candidates pledge to reducing it to 60 or 62.
Denmark's debt to GDP ratio is 27%; France's is 117%.
You reap what you sow.
cnn.com/2025/05/23/business/…
Jonathan A. Parker retweeted
Las acciones de Tesla y SpaceX cayeron luego de conocerse la acción en contra de Ucrania y a pesar del éxito de la presentación del auto volador de Musk.
Las caídas podrían estar originadas en otras noticias como:
- El gobierno de Italia paralizó las negociaciones para adquirir los servicios de Starlink por 1.630 millones de dólares debido a la polémica global en torno a la confiabilidad del servicio y las repetidas amenazas e incidentes de cortes de señal en Ucrania.
-Alemania decidió acelerar el desarrollo de su propia constelación de satélites militares soberanos.
- La presidenta de Renew Europe, Valérie Hayer, y el Comisionado de Defensa de la UE, Andrius Kubilius, declararon que los eventos recientes demuestran la "necesidad urgente de una alternativa europea a Starlink".
-Senadores de los partidos Demócrata y Republicano enviaron una carta oficial dirigida al Inspector General del Departamento de Defensa, exigiendo una investigación formal urgente sobre las restricciones aplicadas a la red. Esto podría afectar a los contratos con el gobierno. SpaceX tiene contratos activos con el gobierno de EEUU por 29.680 millones de dólares.
Dentro del portafolio total de SpaceX con el gobierno, la compañía tiene 8.050 millones de dólares en nuevos contratos militares adjudicados, los cuales están construidos, precisamente, sobre la plataforma y tecnología de su división militar Starshield.
Las acusaciones de Musk a Trump y su respuesta ("No fui yo, y tampoco creo que haya sido Elon") generaron un perjuicio en la reputación del conglomerado.
El costo del apoyo a Putin puede ser mensurado. Elon Musk perdió 28.600 millones de dólares solo por la caída en el valor de las acciones de SpaceX. La caída bursátil de Tesla del 13 al 16 de octubre de 2026 se cuantifica en una pérdida directa de entre 35.000 y 38.000 millones de dólares en capitalización de mercado tomando el valor por acción. Luego está la ganancia no producida del contrato con Italia y la que podría generarse en otros estados que consideran adoptar el sistema.
Queda por ver si Musk insistirá en su estrategia de copiar la agresividad de Trump hacia Ucrania y Zelensky o, como ya sucedió en el pasado, si la presión de los inversores lo llevarán a invertir su decisión, valga la exquisita redundancia.
El consumo de Putin es, como otros vicios extremos, caro y autodestructivo.
Jonathan A. Parker retweeted
Excellent presentation by Sami Petersen and Alberto Undurraga-Flotts, and Claude session summary here: dropbox.com/scl/fi/vrzo60obp…
Jonathan A. Parker retweeted
It's almost as if Econ 101 usually works, and Oren Cass doesn't know anything
Trump’s tariffs raised prices on more than imports. New York Fed researchers found they also pushed up the cost of American-made goods.
Full story here foxnews.com/politics/america…
Jonathan A. Parker retweeted
Mathematician Terence Tao:
"we're seeing the end of the romantic era of mathematics, the age of heroes. we're moving into an industrial era where math becomes large-scale, done in big teams like the other sciences"
We're entering, rather unwillingly, a new era where exciting new things are possible, but some things are being lost
Good finance tweet
You need a diversified portfolio of friends:
> crypto (friends you hide from your parents)
> gold (childhood friends)
> growth stocks (friends with questionable judgment but unlimited potential)
> international (friends with a free place to stay abroad)
> index funds (friends who fit in with any friend group)
> bonds (boring but will pick you up from the airport)
> cash (friends you can call at 2am when everything goes wrong)
> real estate investments (friends who reliably show up once a month)
> meme stocks (friends who are objectively terrible influences but incredibly fun to be around)
Tired: all these young scholars with AI will replace me
Wired: all these young scholars using AI won’t ever learn how to write a good paper so I’m good for another twenty years
The classic case: you start with a weak idea. If you talk and think about it with others, you make progress to better ideas.
If you talk and think about it with AI, it dresses up your idea in economic jargon, contract theory etc., now you have the same bad idea, but it's expressed in enough jargon that it's a little harder to tell that it's a bad idea.
It also looks very impressive, look at all that economic logic! You feel like you're really progressing as an academic thinker and writer, but in fact you're in a much worse place than when you started. 4/
Yes.
China’s economy has harvested the benefits of some capitalism w/ central planning but is now at a crossroads. Planning is increasingly inefficient, eg real estate disaster, & subsidies for EVs are nice but small-time? Do they follow Russia, or Japan, or back to N. Korea?
La URSS colapsó cuando Gorbachov dio señales de que no utilizaría el ejército para frenar los procesos de apertura. Salvando las distancias (la economía china se desacelera y aún tiene margen de estímulo, mientras que la URSS colapsaba), la desaceleración económica podría poner a China frente a la misma encrucijada que vivió la URSS:
1- Si no otorga mayores libertades individuales, la economía encuentra un techo en su potencial de crecimiento.
2- Si otorga mayores libertades, el PCC (Partido Comunista Chino) pierde poder, abriendo las puertas a mayores libertades.
China enfrenta serios desequilibrios estructurales. Si se debilitan las exportaciones, podría entrar en un período de estancamiento similar al de Japón en los 90.
La pregunta es si el PCC puede sostenerse con menor crecimiento económico, qué demandas podrían surgir de las nuevas generaciones y si Xi Jinping recurrirá al nacionalismo (Taiwán) como vía de escape.
Jonathan A. Parker retweeted
The Nobel Prize to Hall and Woodford: A Macroeconomic Journey
conversableeconomist.com/202…
Jonathan A. Parker retweeted
.@elonmusk please tell me these overnight disruptions to Starlink terminals in Ukraine were unintended - that @SpaceX is doing everything it can to fix a temporary glitch.
I'm confident this does not reflect a change in SpaceX policy because if so, intentionally degrading Ukraine's ability to defend itself might be construed as aiding and abetting a mass murderer. Can you confirm that's not SpaceX’s intent?
Ukrainians simply want to live in peace. They did not ask Putin to bomb their homes, schools and hospitals. They do not want Putin to kidnap and brainwash their children. They are not interested in destroying energy infrastructure - in Ukraine or in Russia. They only want to defend their country and live their lives.
Supporting Ukrainian sovereignty - or at the very least, allowing for it - should not be a gray area for the U.S. government or for American corporations. Can you clarify the SpaceX position?
nbcnews.com/world/ukraine/uk…
No.
The lines would flip if you included human wealth. The wealth plotted is only the present value of interest & dividends that the wealth pays. So add the present value of labor income too.
Is it justice to maintain benefits for the old by taxing the lifetime-wealthier young?
Jonathan A. Parker retweeted
The power of unstoppable S-curves: 49 countries hit record Electric Vehicles sales shares in 2026. It's not what you’d expect:
>Viet Nam’s peak share now tops China’s and Sweden’s
>Thailand beats Germany and the UK
>Uruguay beats France
Completely missing: the US, at 6%
ember-energy.org/latest-insi…
Jonathan A. Parker retweeted
When I say "under Trump, the U.S. has switched our alliance from Europe to Russia", I am not exaggerating for rhetorical effect.
Update: Ukraine is reporting that additional speed restrictions have been imposed on Starlink Internet terminals, and communications are lost at speeds of 60 to 70 kph. This essentially wipes out Ukraine’s drone operations through the operational depth. Earlier, restrictions were on StarShield only.
Seems right, no?
cnbc.com/video/2026/10/09/tr…
Debt isn’t the only correlate, but when France asks people to lend them money, wow does it have to promise a high interest rate.
French yields have completely decoupled from the rest of the world. Chart shows the rise in 10-year gov't bond yields above and beyond the global average. France is now in a league of its own and has morphed into an idiosyncratic risk factor for markets...
robinjbrooks.substack.com/p/…
I doubt other fields do PhD admissions as well as economics.
At MIT Sloan finance, multiple faculty read each file, highly-ranked candidates are interviewed 2x, each time by 2 faculty. To avoid bias, we don’t admit our pre-docs. Admission is a committee decision, never lab-level.
Addendum: news.mit.edu/2026/robert-hal…
