school of business and economics discussion on “risk horizon predictors of euro area financial...
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School of Business and Economics
Discussion on “Risk horizon Predictors of Euro Area Financial
Stress” by Thomas Lejeune
Stefan Straetmans
Maastricht University (School
of Business and Economics)
Risk forum Paris, 30-31 March 2015
School of Business and Economics
Discussion in a nutshell
• What is the paper about? • Strengths • Weaknesses
School of Business and Economics
What is the paper about?
• Traditionally (e.g. CAPM, APT, FFC 4-factor model)
“market” risk premium exogenously determined
→ sample average ≈ expected market return • Here: asset pricing model for different risk premia • Nonparametric (model free) approach: no utility
function or distributional return assumptions, only knowledge of first 4 moments assumed
• New concept of risk related to “risk horizon”• Identification of model parameters by use of term structure
model of interest rates• Use of risk premia as EWI in logit models for systemic stress
School of Business and Economics
Strengths • Dazzling analytic level• Novel concept of individual asset risk (“risk horizon”) • Take into account heavy tails via higher moments• Nonparametric character of the approach
→ parsimony in terms of model assumptions reduces
model risk as compared to previous approaches
School of Business and Economics
Weaknesses (1) • “Hermetic” write-up: paper should in principle be
understandable for every financial economist
(not necessarily a specialist in asset pricing) • Journal you want to submit?
→ if it is for a specialized math journal, OK
→ if mainstream finance journal, more intuition
explanation necessary
→ three more or less concentrically overlapping papers; fine for a phd thesis but what about a journal article? You refer a lot to previously unpublished research, make one master paper out of this?
School of Business and Economics
Weaknesses (2) • How accurate is the Chebyshev upper bound? Is extreme
value analysis (EVT) more accurate alternative?• Simplifying assumptions need more explanation
- concept of risk horizon
- knowledge of 2nd-4th moment also characterized
by estimation risk
- estimates of the tail index of financial returns suggest:
- α is the number of bounded moments
- in other words: the variance seems to exist but the kurtosis often does not!
43ˆ2
School of Business and Economics
Weaknesses (3) • Accuracy of risk factors? Confidence bands?• Tables 5-6: after adding controls, only credit trend stays
significant as EWI, it seems• Tables 5-6: why does the credit trend coefficient
become so huge (in absolute value) after adding controls? • Logit output
- way too many tables!
- discuss marginal logit effects
- lots of controls, lack of parsimony
- correlation, multicollinearity of control variables?
- without control variables, pseudo-R2 low
- static vs. dynamic logit (lagged dependent variable)
School of Business and Economics
All in all • High potential paper • Should be readable for a wider audience than asset
pricing except if you focus on very specialized journal