Papers

January 2015 | Article

Four Types of Ignorance

Lars Peter Hansen, Thomas J. Sargent

This paper studies alternative ways of representing uncertainty about a law of motion in a version of a classic macroeconomic targetting problem of Milton Friedman (1953). We study both “unstructured uncertainty” – ignorance of the conditional distribution of the target next period as a function of states and controls – and more “structured uncertainty” – ignorance of the probability distribution of a response coefficient in an otherwise fully trusted specification of the conditional distribution of next period׳s target. We study whether and how different uncertainties affect Friedman׳s advice to be cautious in using a quantitative model to fine tune macroeconomic outcomes.

Journal: Journal of Monetary Economics|Volume: 69|Issue Number: January|Pages: 97-113|Tags: Risk, Robustness and Ambiguity|Export BibTeX >
@article{hansensargent:2015,
  title={Four Types of Ignorance},
  author={Hansen, Lars Peter and Sargent, Thomas J.},
  journal={Journal of Monetary Economics},
  volume={69},
  pages={97--113},
  year={2015},
  publisher={Elsevier}
}
November 2014 | Article

Examining Macroeconomic Models Through the Lens of Asset Pricing

Jaroslav Borovička, Lars Peter Hansen

Dynamic stochastic equilibrium models of the macro economy are designed to match the macro time series including impulse response functions. Since these models aim to be structural, they also have implications for asset pricing. To assess these implications, we explore asset pricing counterparts to impulse response functions. We use the resulting dynamic value decomposition (DVD) methods to quantify the exposures of macroeconomic cash flows to shocks over alternative investment horizons and the corresponding prices or compensations that investors must receive because of the exposure to such shocks. We build on the continuous-time methods developed in Hansen and Scheinkman (2010), Borovicka et al. (2011) and Hansen (2011) by constructing discrete-time shock elasticities that measure the sensitivity of cash flows and their prices to economic shocks including economic shocks featured in the empirical macroeconomics literature. By design, our methods are applicable to economic models that are nonlinear, including models with stochastic volatility. We illustrate our methods by analyzing the asset pricing model of Ai et al. (2010) with tangible and intangible capital.

Journal: Journal of Econometrics|Volume: 183|Issue Number: 1|Pages: 67-90|Tags: Financial Market Linkages to the Macroeconomy, Uncertainty and Valuation|Export BibTeX >
@article{borovivckahansen:2014,
  title={Examining Macroeconomic Models Through the Lens of Asset Pricing},
  author={Borovi{v{c}}ka, Jaroslav and Hansen, Lars Peter},
  journal={Journal of Econometrics},
  volume={183},
  number={1},
  pages={67--90},
  year={2014},
  publisher={Elsevier}
}
September 2014 | Article

Shock Elasticities and Impulse Responses

Jaroslav Borovička, Lars Peter Hansen, Jose A. Scheinkman

We construct shock elasticities that are pricing counterparts to impulse response functions. Recall that impulse response functions measure the importance of next-period shocks for future values of a time series. Shock elasticities measure the contributions to the price and to the expected future cash flow from changes in the exposure to a shock in the next period. They are elasticities because their measurements compute proportionate changes. We show a particularly close link between these objects in environments with Brownian information structures.

Journal: Mathematics and Financial Economics|Volume: 8|Issue Number: 4|Pages: 333-354|Tags: Financial Market Linkages to the Macroeconomy, Uncertainty and Valuation|Export BibTeX >
@article{bhs:2014,
  title={Shock Elasticities and Impulse responses},
  author={Borovi{v{c}}ka, Jaroslav and Hansen, Lars Peter and Scheinkman, Jos{'e} A},
  journal={Mathematics and Financial Economics},
  volume={8},
  number={4},
  pages={333--354},
  year={2014},
  publisher={Springer}
}
July 2014 | Article

Uncertainty Outside and Inside Economic Models (Nobel Lecture)

Lars Peter Hansen

“We must infer what the future situation would be without our interference, and what changes will be wrought by our actions. Fortunately, or unfortunately, none of these processes is infallible, or indeed ever accurate and complete.”  Knight (1921)

Journal: Journal of Political Economy|Volume: 122|Issue Number: 5|Pages: 945-987|Tags: Econometrics, Financial Market Linkages to the Macroeconomy, Risk, Robustness and Ambiguity, Uncertainty and Valuation|Export BibTeX >

@article{hansen:2014},
Author = {Hansen, Lars},
Date-Added = {2016-03-28 00:37:47 +0000},
Date-Modified = {2016-03-28 00:40:13 +0000},
Journal = {Journal of Political Economy},
Number = {5},
Pages = {945 – 987},
Title = {Nobel Lecture: Uncertainty Outside and Inside Economic Models},
Url = {http://EconPapers.repec.org/RePEc:ucp:jpolec:doi:10.1086/678456},
Volume = {122},
Year = {2014},
Bdsk-Url-1 = {http://EconPapers.repec.org/RePEc:ucp:jpolec:doi:10.1086/678456}}

January 2013 | Chapter

Risk Pricing over Alternative Investment Horizons

Lars Peter Hansen

I explore methods that characterize model-based valuation of stochastically growing cash flows. Following previous research, I use stochastic discount factors as a convenient device to depict asset values. I extend that literature by focusing on the impact of compounding these discount factors over alternative investment horizons. In modeling cash flows, I also incorporate stochastic growth factors. I explore dynamic value decomposition (DVD) methods that capture concurrent compounding of a stochastic growth and discount factors in determining risk-adjusted values. These methods are supported by factorizations that extract martingale components of stochastic growth and discount factors. These components reveal which ingredients of a model have long-term implications for valuation. The resulting martingales imply convenient changes in measure that are distinct from those used in mathematical finance, and they provide the foundations for analyzing model-based implications for the term structure of risk prices. As an illustration of the methods, I re-examine some recent preference based models. I also use the martingale extraction to revisit the value implications of some benchmark models with market restrictions and heterogenous consumers.

Pages: 1571-1611|Title of book: Handbook of the Economics of Finance|Editor(s): George M Constantinides, Milton Harris, and René M Stulz|Place of Publication: Amsterdam|Publisher: North Holland|Tags: Uncertainty and Valuation|Export BibTeX >
@article{hansen:2012risk,
  title={Risk Pricing Over Alternative Investment Horizons},
  author={Hansen, Lars Peter},
  year={2012}
}
November 2012 | Chapter

Challenges in Identifying and Measuring Systemic Risk

Lars Peter Hansen

Sparked by the recent “great recession” and the role of financial markets, considerable interest exists among researchers within both the academic community and the public sector in modeling and measuring systemic risk. In this essay I draw on experiences with other measurement agendas to place in perspective the challenge of quantifying systemic risk, or more generally, of providing empirical constructs that can enhance our understanding of linkages between financial markets and the macroeconomy.

Title of book: Risk Topography: Systemic Risk and Macro Modeling|Editor(s): Markus Konrad Brunnermeier and Arvind Krishnamurthy|Place of Publication: Chicago|Publisher: University of Chicago Press|Tags: Financial Market Linkages to the Macroeconomy|Export BibTeX >
@techreport{hansen:2012challenges,
  title={Challenges in Identifying and Measuring Systemic Risk},
  author={Hansen, Lars Peter},
  year={2012},
  institution={National Bureau of Economic Research}
}
October 2012 | Article

Proofs for Large Sample Properties of Generalized Method of Moments Estimators

Lars Peter Hansen

I present proofs for the consistency of generalized method of moments (GMM) estimators presented in Hansen (1982). Some basic approximation results provide the groundwork for the analysis of a class of such estimators. Using these results, I establish the large sample convergence of GMM estimators under alternative restrictions on the estimation problem.

Journal: Journal of Econometrics|Volume: 170|Issue Number: 2|Pages: 325-330|Tags: Econometrics|Export BibTeX >
@article{hansen:2012proofs,
  title={Proofs for Large Sample Properties of Generalized Method of Moments Estimators},
  author={Hansen, Lars Peter},
  journal={Journal of Econometrics},
  volume={170},
  number={2},
  pages={325--330},
  year={2012},
  publisher={Elsevier}
}
October 2012 | Article

Underidentification?

Manuel Arellano, Lars Peter Hansen, Enrique Sentana

We develop methods for testing that an econometric model is underidentified and for estimating the nature of the failed identification. We adopt a generalized-method-of moments perspective in a possibly non-linear econometric specification. If, after attempting to replicate the structural relation, we find substantial evidence against the overidentifying restrictions of an augmented model, this is evidence against underidentification of the original model. To diagnose how identification might fail, we study the estimation of a one-dimensional curve that gives the parameter configurations that provide the greatest challenge to identification, and we illustrate this calculation in an empirical example.

Journal: Journal of Econometrics|Volume: 170|Issue Number: 2|Pages: 256-280|Tags: Econometrics|Export BibTeX >

@article{arellanohansensentana:2012,

title={Underidentification?},

author={Arellano, Manuel and Hansen, Lars Peter and Sentana, Enrique},

journal={Journal of Econometrics},

volume={170},

number={2},

pages={256–280},

year={2012},

publisher={Elsevier}

}

July 2012 | Article

Three Types of Ambiguity

Lars Peter Hansen, Thomas J. Sargent

For each of three types of ambiguity, we compute a robust Ramsey plan and an associated worst-case probability model. Ex post, ambiguity of type I implies endogenously distorted homogeneous beliefs, while ambiguities of types II and III imply distorted heterogeneous beliefs. Martingales characterize alternative probability specifications and clarify distinctions among the three types of ambiguity. We use recursive formulations of Ramsey problems to impose local predictability of commitment multipliers directly. To reduce the dimension of the state in a recursive formulation, we transform the commitment multiplier to accommodate the heterogeneous beliefs that arise with ambiguity of types II and III. Our formulations facilitate comparisons of the consequences of these alternative types of ambiguity.

Journal: Journal of Monetary Economics|Volume: 59|Issue Number: 5|Pages: 422-445|Tags: Risk, Robustness and Ambiguity|Export BibTeX >
@article{hansensargent:2012three,
  title={Three Types of Ambiguity},
  author={Hansen, Lars Peter and Sargent, Thomas J.},
  journal={Journal of Monetary Economics},
  volume={59},
  number={5},
  pages={422--445},
  year={2012},
  publisher={Elsevier}
}
July 2012 | Article

Recursive Utility in a Markov Environment with Stochastic Growth

Lars Peter Hansen, Jose A. Sheinkman

Recursive utility models that feature investor concerns about the intertemporal composition of risk are used extensively in applied research in macroeconomics and asset pricing. These models represent preferences as the solution to a nonlinear forward-looking difference equation with a terminal condition. In this paper we study infinite-horizon specifications of this difference equation in the context of a Markov environment. We establish a connection between the solution to this equation and to an arguably simpler Perron–Frobenius eigenvalue equation of the type that occurs in the study of large deviations for Markov processes. By exploiting this connection, we establish existence and uniqueness results. Moreover, we explore a substantive link between large deviation bounds for tail events for stochastic consumption growth and preferences induced by recursive utility.

Journal: Proceedings of the National Academy of Sciences|Volume: 109|Issue Number: 30|Pages: 11967-11972|Tags: Financial Market Linkages to the Macroeconomy, Uncertainty and Valuation|Export BibTeX >
@article{hansenscheinkman:2012recursive,
  title={Recursive Utility in a Markov Environment With Stochastic Growth},
  author={Hansen, Lars Peter and Scheinkman, Jos{'e} A},
  journal={Proceedings of the National Academy of Sciences},
  volume={109},
  number={30},
  pages={11967--11972},
  year={2012},
  publisher={National Acad Sciences}
}