Jonathan A. Parker
@profjaparker.bsky.social
Economist. Evidence-based economics and finance, humor, and frustration with extremism and divisiveness.
http://mitmgmtfaculty.mit.edu/japarker/
to verify that this is me.
http://mitmgmtfaculty.mit.edu/japarker/
to verify that this is me.
Sometimes I leave campus and discover that MIT does not have a monopoly on creating breathtaking innovations in America
January 2, 2026 at 9:08 PM
Sometimes I leave campus and discover that MIT does not have a monopoly on creating breathtaking innovations in America
2025 sucked. And it’s going out true to form.
January 1, 2026 at 3:15 AM
2025 sucked. And it’s going out true to form.
Reposted by Jonathan A. Parker
Reposted by Jonathan A. Parker
Denmark lost more troops per capita in the post 9/11 war on Afghanistan. Saying they “are not a good ally” because they won’t surrender their territories to the US is lunacy. We are betraying our allies to satisfy the whims of a would-be Emperor for whom the US is not enough.
They’re again advocating against Denmark when it comes to Greenland
December 27, 2025 at 4:13 PM
Denmark lost more troops per capita in the post 9/11 war on Afghanistan. Saying they “are not a good ally” because they won’t surrender their territories to the US is lunacy. We are betraying our allies to satisfy the whims of a would-be Emperor for whom the US is not enough.
Short days, but not so bleak midwinter in Belmont
December 24, 2025 at 10:24 PM
Short days, but not so bleak midwinter in Belmont
In memorial, a hat tip to one of my favorite all-time papers. In intertemporal problems, the second welfare theorem is generically false. I prefer the version before it got revised for the JPE, which was not purely about revealed preference. But there is JPE
www.journals.uchicago.edu/doi/abs/10.1...
www.journals.uchicago.edu/doi/abs/10.1...
The Social Discount Rate | Journal of Political Economy: Vol 112, No 6
What discount rate should be applied to social investments? It is standard to use the market interest rate, thereby respecting private preferences. We show that application of this “revealed preferenc...
www.journals.uchicago.edu
December 22, 2025 at 10:59 PM
In memorial, a hat tip to one of my favorite all-time papers. In intertemporal problems, the second welfare theorem is generically false. I prefer the version before it got revised for the JPE, which was not purely about revealed preference. But there is JPE
www.journals.uchicago.edu/doi/abs/10.1...
www.journals.uchicago.edu/doi/abs/10.1...
My colleagues think this is mostly show and fluff, not important, but I was more uncertain due to the connection to financial markets and saving and wealth-building . . .
December 17, 2025 at 10:21 PM
My colleagues think this is mostly show and fluff, not important, but I was more uncertain due to the connection to financial markets and saving and wealth-building . . .
The return of SSCI?
Grading and googling hallucinated citations, as one does nowadays, and now that LLMs have been around for a while, I've discovered new horrors: hallucinated journals are now appearing in Google Scholar with dozens of citations bc so many people are citing these fake things
December 15, 2025 at 11:37 PM
The return of SSCI?
Early in 2025, I saw a recession as more likely than not. Three things broke so that the economy slowed but never shrank.
1) Trump cost cutting failed, huge deficit 6% of GDP
2) AI+ boom in investment & stocks
3) The Fed was loose, tolerating inflation rate 1.5 times target
1) Trump cost cutting failed, huge deficit 6% of GDP
2) AI+ boom in investment & stocks
3) The Fed was loose, tolerating inflation rate 1.5 times target
December 15, 2025 at 12:51 PM
Early in 2025, I saw a recession as more likely than not. Three things broke so that the economy slowed but never shrank.
1) Trump cost cutting failed, huge deficit 6% of GDP
2) AI+ boom in investment & stocks
3) The Fed was loose, tolerating inflation rate 1.5 times target
1) Trump cost cutting failed, huge deficit 6% of GDP
2) AI+ boom in investment & stocks
3) The Fed was loose, tolerating inflation rate 1.5 times target
Send this to every progressive and MAGA tariff-lover: www.thefreedomfrequency.org/p/the-troubl...
The Trouble with Tariffs
Why free trade benefits everyone.
www.thefreedomfrequency.org
December 15, 2025 at 1:18 AM
Send this to every progressive and MAGA tariff-lover: www.thefreedomfrequency.org/p/the-troubl...
Reposted by Jonathan A. Parker
Here is what Trump and his enablers fail to understand: Immigrants love this country deeply. We love democracy. We cherish the rule of law, the promise of due process and the idea that our diversity is a strength, not a threat.
My op-ed:
My op-ed:
Opinion | Rep. Ilhan Omar: Trump's slurs seek to cast suspicion on anyone who isn't white
The president's attacks and ICE activity in Minnesota are weaponizing fear against me and other immigrants.
www.ms.now
December 14, 2025 at 10:08 PM
Here is what Trump and his enablers fail to understand: Immigrants love this country deeply. We love democracy. We cherish the rule of law, the promise of due process and the idea that our diversity is a strength, not a threat.
My op-ed:
My op-ed:
Reposted by Jonathan A. Parker
Veteran detained by ICE: I identified myself as a US citizen and a veteran, but that didn't matter. Agents smashed my window, sprayed tear gas into my car, dragged me out. Even after I complied, I was held for 3 days without charges. No phone call, no lawyer, no medical care
December 10, 2025 at 4:24 PM
Veteran detained by ICE: I identified myself as a US citizen and a veteran, but that didn't matter. Agents smashed my window, sprayed tear gas into my car, dragged me out. Even after I complied, I was held for 3 days without charges. No phone call, no lawyer, no medical care
From Apollo. I would’ve done five years ahead, which has a less good fit, but also less overlapping data, but the main point stands: for the longer-term investor, the stock market has a lower expected return than bonds, and more variance.
December 11, 2025 at 12:43 PM
From Apollo. I would’ve done five years ahead, which has a less good fit, but also less overlapping data, but the main point stands: for the longer-term investor, the stock market has a lower expected return than bonds, and more variance.
Our national debt and prospective deficits are in the “getting the gang together and choosing their weapons” scene in the movie, right before they go to work on our economy.
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https%3A%2F%2Fmedia1.giphy.com%2Fmedia%2F1eEv7v51FEI3L54jpr%2Fgiphy.gif
external-content.duckduckgo.com
December 10, 2025 at 3:55 PM
Our national debt and prospective deficits are in the “getting the gang together and choosing their weapons” scene in the movie, right before they go to work on our economy.
https%3A%2F%2Fmedia1.giphy.com%2Fmedia%2F1eEv7v51FEI3L54jpr%2Fgiphy.gif
https%3A%2F%2Fmedia1.giphy.com%2Fmedia%2F1eEv7v51FEI3L54jpr%2Fgiphy.gif
Great pre-doc positions at MIT Sloan for those interested in economic research:
apply.interfolio.com/176006
apply.interfolio.com/177709
apply.interfolio.com/176006
apply.interfolio.com/177709
Apply - Interfolio
{{$ctrl.$state.data.pageTitle}} - Apply - Interfolio
apply.interfolio.com
December 9, 2025 at 1:19 AM
Great pre-doc positions at MIT Sloan for those interested in economic research:
apply.interfolio.com/176006
apply.interfolio.com/177709
apply.interfolio.com/176006
apply.interfolio.com/177709
Breaking: Francesca Gino to receive @FIFAWorldCup prize in economics
December 7, 2025 at 7:59 PM
Breaking: Francesca Gino to receive @FIFAWorldCup prize in economics
Personal tweet: give this song a listen— first release from The Badgers co-written by my cousin (Felix Fry, also on drums). Check them out if you’re in London.
open.spotify.com/track/4pjWWB...
open.spotify.com/track/4pjWWB...
Spotify – Web Player
open.spotify.com
December 7, 2025 at 4:43 PM
Personal tweet: give this song a listen— first release from The Badgers co-written by my cousin (Felix Fry, also on drums). Check them out if you’re in London.
open.spotify.com/track/4pjWWB...
open.spotify.com/track/4pjWWB...
Boston from MIT Sloan, December, at dusk
December 2, 2025 at 11:18 PM
Boston from MIT Sloan, December, at dusk
Hmmm. Hints of people losing faith in the economic institutions of our country.
Unfortunately, lots of other hints too, like www.ft.com/content/beaa...
Unfortunately, lots of other hints too, like www.ft.com/content/beaa...
December 1, 2025 at 1:16 PM
Hmmm. Hints of people losing faith in the economic institutions of our country.
Unfortunately, lots of other hints too, like www.ft.com/content/beaa...
Unfortunately, lots of other hints too, like www.ft.com/content/beaa...
New book from my brilliant classmate!!
Designed for an introductory course in probability and statistics for economics and business undergraduates, Jason @abrevaya.bsky.social's textbook "Probability and Statistics for Economics and Business" introduces students to the R statistical programming language: mitpress.mit.edu/978026255336...
November 29, 2025 at 10:53 PM
New book from my brilliant classmate!!
Humor alive and well in these groveling times . . .
As a son of Appalachia, I understand the opioid crisis better than anyone. That's why I'm proud to stand with the Honduran president who delivered drugs to needy Americans with such efficiency.
by JD Vance
by JD Vance
November 29, 2025 at 5:39 PM
Humor alive and well in these groveling times . . .
Come on @nytimes, just disagree respectfully with recent applied micro, don’t call it LATE dementia
November 28, 2025 at 10:25 PM
Come on @nytimes, just disagree respectfully with recent applied micro, don’t call it LATE dementia
All these people . . . Maybe they should build a large online retailer and compete, rather than trying to cut down the Amazon
🌏Historic day of action as workers and allies took the streets around the world to demand justice from Amazon. The movement keeps growing — and so does our resolve to win. ✊ #MakeAmazonPay.
November 28, 2025 at 3:55 PM
All these people . . . Maybe they should build a large online retailer and compete, rather than trying to cut down the Amazon