Macroeconomics

We develop a theory of optimal government debt in which publicly-issued and privately-issued safe assets are substitutes. While government bonds are backed by future tax revenues, privately-issued safe assets are backed by the future repayment of pools of defaultable private loans. We find that a higher supply of public debt crowds out privately-issued safe assets less than one for one and reduces the interest spread between borrowing and deposit rates.

We develop a two-state hidden Markov model where the process driving market returns transitions between turbulent and calm states. A cross-sectional momentum strategy embeds a call option on the market, inducing a state-contingent convex relation between market and momentum returns. In turbulent states, the short side of the momentum strategy has high beta and convexity with respect to the market, as a result of higher effective leverage of the past-loser securities, making momentum crashes more likely.

We study optimal savings policies when there is a dual concern about under-saving for retirement and income inequality. Agents differ in time preferences and earnings ability, both unobservable to a planner with paternalistic and redistributive motives. We characterize the solution to this two-dimensional screening problem and provide a decentralization using realistic policy instruments: forced savings at low incomes — similar to Social Security — but a choice between savings accounts with different subsidies and caps at high incomes — like 401(k) and IRA accounts in the US.

Being a successful manager or entrepreneur in the media and digital sector requires creativity, innovation, and performance. It also requires an understanding of the principles and tools of management. Aimed at the college market, this book is a short, foundational volume on media management. It summarizes the major dimensions of a business school curriculum and applies them to the entire media, media-tech, and digital sector. Its chapters cover—in a jargonless, non-technical way—the major functions of management.

Over the past four decades, government debt as a fraction of GDP has been on an upward trajectory in advanced economies, approaching levels not reached since World War II. While normative macroeconomic theories can explain the increase in the level of debt in certain periods as a response to macroeconomic shocks, they cannot explain the broad-based long-run trend in debt accumulation. In contrast, political economy theories can explain the long-run trend as resulting from an aging population, rising political polarization, and rising electoral uncertainty across advanced economies.

The problem of optimally designing information for multiple agents who interact in a game can be formulated as a linear program. We explore its dual representation and show that it provides a novel perspective and new economic insights into the information-design problem. Through the lens of the dual, we identify general properties that hold for all information-design problems. Duality also offers a portable, general, method for computing solutions. We illustrate this approach in the context of simple investment games.

Although the rates of economic inequality in the United States are at their highest since the onset of The Great Depression, many Americans do not seem as concerned as may be expected. This apparent lack of concern has been attributed to people's deeply-entrenched belief in economic mobility -- the belief that through hard work, determination, and skill people are able to rise up the economic ladder. Little is known, however, about why Americans so strongly believe in economic mobility.

Pricing greenhouse gas emissions involves making trade-offs between consumption today and unknown damages in the (distant) future. This setup calls for an optimal control model to determine the carbon dioxide (CO2) price. It also relies on society's willingness to substitute consumption across time and across uncertain states of nature, the forte of Epstein-Zin preference specifications.

Governments are present-biased toward spending. Fiscal rules are deficit limits that trade off commitment to not overspend and flexibility to react to shocks. We compare coordinated rules, chosen jointly by a group of countries, to uncoordinated rules. If governments' present bias is small, coordinated rules are tighter than uncoordinated rules: individual countries do not internalize the redistributive effect of interest rates. However, if the bias is large, coordinated rules are slacker: countries do not internalize the disciplining effect of interest rates.