About

Jonathan A. Parker is the Robert C. Merton (1970) Professor of Financial Economics at MIT Sloan School of Management. He serves as a co-director of both the MIT Sloan Consumer Finance Initiative and the MIT Golub Center for Finance and Policy, and is the Area Head of Economics, Finance, and Accounting. His expertise encompasses finance, macroeconomics, and household behavior, with a focus on macroeconomic risks, asset returns, household financial decisions, fiscal stabilization policy, national saving, business cycle measurement, and modeling human economic behavior. His current research broadly addresses household finance, FinTech, financial markets, retirement financing, macroeconomics, and public policy. A significant part of his work involves documenting the role of liquidity in household spending decisions. His recent research topics include measuring household portfolios, risk-taking, beliefs, machine learning applications for household portfolios, the impact of household financial innovations on stock market dynamics, and analyzing the effects of the COVID-19 crisis and policy responses on Americans' living standards and small business owners. Parker has received recognition for his scholarly contributions, including the 2024 TIAA Paul A. Samuelson Award for Outstanding Scholarly Writing on Lifelong Financial Security.

Research topics

• Economics
• Business
• Computer Science
• Finance
• Microeconomics
• Monetary economics
• Mathematical economics
• Macroeconomics
• Financial economics
• Mathematics
• Actuarial science
• Econometrics
• Mathematical optimization

Selected publications

• Revenue collapses and the consumption of small business owners in the COVID-19 pandemic

  Journal of Financial Economics · 2025-05-10 · 1 citations

  article
  PublisherDOI

• Household Portfolios and Retirement Saving over the Life Cycle

  The Journal of Finance · 2025-08-12 · 5 citations

  articleOpen access1st authorCorresponding

  ABSTRACT Using account‐level data on millions of U.S. middle‐class investors over 2006 to 2018, we characterize the share of investable wealth that they hold in the stock market over their working lives. Relative to the 1990s, this share has both risen by 10% and become age‐dependent. The Pension Protection Act (PPA)—which allowed target date funds (TDFs) to be default options in retirement plans—played an important role: younger (older) workers starting at a firm after TDFs became the default option post‐PPA invested more (less) in stocks, in line with the TDF glidepath. In contrast, contribution rates changed little following the PPA.

  PublisherOA PDFDOI

• Correction to: A Dynamic Theory of Lending Standards

  Review of Financial Studies · 2024

  • Computer Science
  • Computer Science
  • Mathematical economics

  We only focus on slow thawing in the region between x s and 1.Note that a similar region with slow thawing can also appear in the region between x and x s and slow down the convergence to the screening steady state from the left."

  DOI

• Surgical window of opportunity clinical trial of abemaciclib and letrozole for endometrioid adenocarcinoma of the endometrium.

  Journal of Clinical Oncology · 2024-06-01

  article

  5596 Background: Abemaciclib inhibits cyclin dependent kinases (CDK) 4 and 6 and, in synergy with anti-estrogens, is an FDA approved treatment of ER+ breast cancer. Endometrioid endometrial cancer frequently express the estrogen receptor and harbors PTEN, PI3K, KRAS and CTNNB1 mutations which induce estrogen-mediated upregulation of cyclin D1 and cancer cell proliferation. We hypothesized that the combination of letrozole and abemaciclib will inhibit cellular proliferation, as measured by Ki-67, in patients with endometrial cancer. Methods: This is a single-arm prospective multicenter surgical window of opportunity clinical trial for patients with endometrial cancer planned to undergo definitive surgical management with hysterectomy. Eligibility criteria included endometrioid histology, no prior treatment for endometrial cancer, and a window of greater than 15 days prior to scheduled hysterectomy. Patients received 14 days of abemaciclib 150mg twice daily and letrozole 2.5mg once daily. The primary endpoint was change in Ki-67 (%) from pretreatment biopsy to posttreatment hysterectomy specimen. Secondary endpoints included biological tumor characteristics (MMR, PTEN, PI3K, cyclin D1, pRB) associated with Ki-67 changes. The planned sample size was n=21 evaluable patients which would achieve 80% power with two-sided α = 0.05 to detect a 12.9% decrease in Ki67 expression based on a paired t-test. Results: A total of 27 women were enrolled, 2 patients withdrew consent leaving 25 evaluable patients. The median age was 62 (IQR: 54 - 66) and 19 patients (76%) were menopausal. Most patients were White (68%), 24% identified as Black; 20% were of Hispanic ethnicity. Median BMI was 37 (IQR: 30-40). All cancers were endometrioid with the majority being FIGO grade 1 (76%) and 24% grade 2. Nine (33%) patients had mismatch repair deficient tumors. Twenty-two (88%) patients were stage I, two (8%) stage II, and 1 (4%) stage IV. Mean baseline Ki-67 was 34% (SD 22%). After 2 weeks of treatment with abemaciclib and letrozole mean Ki67 was 14% (SD 16%). The mean Ki-67 reduction was 19% (SD 23%, p<0.001) meeting the prespecified endpoint. We found no significant difference in the magnitude of Ki-67 reduction based upon present or absent staining for pRb, PTEN, cyclin D1, p16, or MMR proteins. Post-menopausal patients had a decrease in Ki-67 of 26% compared to 15% for those who were premenopausal, but this did not reach statistical significance (p=0.5). There were no serious adverse events recorded. The most common study related adverse events were grade 1-2 diarrhea (68%) and grade 1-2 nausea (36%). Two patients had grade 3 hematological events (anemia and neutropenia), which resolved. Conclusions: Abemaciclib and letrozole induced a reduction in cellular proliferation in endometrioid endometrial cancer over a relatively short two week time period prior to surgery, suggesting clinical efficacy. Clinical trial information: NCT04049227 .

  PublisherDOI

• A Dynamic Theory of Lending Standards

  Review of Financial Studies · 2024 · 7 citations

  • Economics
  • Monetary economics
  • Business

  Abstract We analyze a dynamic credit market where banks choose lending standards, modeled as costly effort to screen out bad borrowers. Tighter standards worsen the borrower pool, increasing banks’ incentives to employ tight standards in the future. This dynamic complementarity in lending standards can amplify and prolong downturns, decreasing lending and increasing credit spreads. Because lending standards have negative externalities, the market can converge to a steady state with inefficiently tight lending standards. We discuss the role of optimal policy to avoid this outcome as well as the impact of balance sheet costs on lending standards.

  PublisherOA PDFDOI

• Target Date Funds as Asset Market Stabilizers: Evidence from the Pandemic

  SSRN Electronic Journal · 2023-01-01

  articleOpen access1st authorCorresponding
  PublisherDOI

• Comment

  NBER Macroeconomics Annual · 2023-05-01

  article1st authorCorresponding
  PublisherDOI

• Target date funds as asset market stabilizers: evidence from the pandemic

  Journal of Pensions Economics and Finance · 2023-11-03 · 8 citations

  articleOpen access1st authorCorresponding

  Abstract Target date funds (TDFs) provide retirement investors, many of whom are unsophisticated or inattentive, with age-appropriate exposures to different asset classes like stocks and bonds. To maintain exposures, TDFs trade actively against market returns, buying stock funds when the stock market does poorly, and selling when the market does well (Parker et al ., 2023, Journal of Finance ). This paper shows that trading by TDFs was a significant stabilizing force in US equity markets during the unprecedented economic volatility of the COVID-19 pandemic period. Specifically, TDFs – now comprising a quarter of all 401(k) plan assets – caused significant contrarian investment flows across asset classes, flows that were not undone by enrollment of TDF investors or by discretionary actions by TDF managers. Mutual funds with large ownership by TDFs had more stable funding through the pandemic, and stocks that had greater indirect ownership by TDFs had lower co-movement with the market and lower volatility during the pandemic period.

  PublisherOA PDFDOI

• Retail Financial Innovation and Stock Market Dynamics: The Case of Target Date Funds

  The Journal of Finance · 2023-06-19 · 52 citations

  article1st author

  ABSTRACT Target date funds (TDFs) are designed to provide unsophisticated or inattentive investors with age‐appropriate exposures to different asset classes like stocks and bonds. The rise of TDFs has moved a significant share of retirement investors into macrocontrarian strategies that sell stocks after relatively good stock market performance. This rebalancing drives contrarian flows across equity mutual funds held by TDFs, stabilizing their funding, and reduces stock returns for stocks disproportionately held by these funds when stock market returns are relatively high. Continued growth in TDFs and similar investment products may dampen stock market volatility and increase the transmission of shocks across asset classes.

  PublisherDOI

• Target Date Funds as Asset Market Stabilizers: Evidence from the Pandemic

  National Bureau of Economic Research · 2023-08-01 · 4 citations

  reportOpen access1st authorCorresponding

  Target Date Funds (TDFs) provide retirement investors, many of whom are unsophisticated or inattentive, with age-appropriate exposures to different asset classes like stocks and bonds. To maintain exposures, TDFs trade actively against market returns, buying stock funds when the stock market does poorly, and selling when the market does well (Parker, Schoar, and Sun, 2023). This paper shows that trading by TDFs was a significant stabilizing force in US equity markets during the unprecedented economic volatility of the COVID-19 pandemic period. Specifically, TDFs – now comprising a quarter of all 401(k) plan assets – caused significant contrarian investment flows across asset classes, flows that were not undone by enrollment of TDF investors or by discretionary actions by TDF managers. Mutual funds with large ownership by TDFs had more stable funding through the pandemic, and stocks that had greater indirect ownership by TDFs had lower co-movement with the market and lower volatility during the pandemic period.

  PublisherDOI

Frequent coauthors

• Nicholas S. Souleles

  83 shared

• David Johnson

  45 shared

• Susanto Basu

  36 shared

• John M. Abowd

  36 shared

• Robert C. Feenstra

  University of California, Davis

  36 shared

• Ana Aizcorbe

  Bureau of Economic Analysis

  36 shared

• Karen E. Dynan

  36 shared

• Randall S. Kroszner

  36 shared

Awards & honors

• 2024 TIAA Paul A. Samuelson Award for Outstanding Scholarly…