26.3 Approaches to Modeling the Cycle
3 approach:
Below show the importance of the dimension to each style:
Data quantity, variety and complexity
Soft > Behavioral > Technical
Recognition of human factors
Soft > Behavioral > Technical
Mathematical formalism and rigor
Technical > Behavioral > Soft
Before we model, first we define what it is we want to know and look for leading indicators that foretell the turn in the cycle:
Criterion Variable
What variable we are interested in?
Conceptually we want price
e.g. Price to coer a standard risk
But impossible to define in insurance
Use loss ratio or combined ratio etc as a proxy
- Maybe with adjustments for TVM (e.g. include investment income)
Predictor Variable:
Information available to calculate the current period criterion and also forecast the forward period criterion
Historical criterion variable and it’s components:
(e.g. loss, expense)
Internal financial variables:
(e.g. reserve, capital, capital flow, reinsurance cessions)
Regulatory rating variables:
(e.g. downgrades and upgrades)
Reinsurance sector financials:
(e.g. capital held by reinsurers)
Econometric variable:
(e.g. inflation, unemployment, GDP)
Financial market variables:
(e.g. interest rates, stock market returns)
Competitor Intelligence:
Gather information on customers at renewal time and competitors (e.g. Firm’s own agents, customere surveys at renewal, trade publications/news, rate filing)
Provides more detailed information on the state of the u/w cycle
Need to beware of antitrust and legal issues (e.g. industrial spying)
Goal is to look for leading indicatiors that foretell the turn in the cycle
26.3.1 Soft Approach
Starts with intense focus on data gathering and intelligence
Goal: Give analysts insight into the complex u/w cycle
- Collect as much information as we can
This is a human approach, focused on three methods:
Scenarios
Detailed written statement describing a possible future state of the world
Help company think about how it might respond to different future states
Goal is to have a detailed description of the environment and analyzed by minds
Delphi Method
Gather expert opinion without biasing the group to the opinion of the most senior persons
Process:
Give background to participants
Gather opinions using questionnaire
Results are summarized and distributed
Allow participants to reconsider and articulate reason for disagreeing
Repeat until consensus is reached
Formal Competitor Analysis
First determine current state, motives, and likely behavior for the main competitors
Need database of competitor information that has key financials, new items, and behavioral metrics
Overtime, distinction between normal and abnormal statistics becomes evident
Key to predicting turns in the u/w cycle is unusually profitable or distressed financial conditions reproduced over a large number of firms
26.3.2 Technical Approach
Focus here is on a small number of industry financial statistics (possibly only 1)
- We have at best only a rudimentary theory underlying the model
Autoregressive Model
Research shown cycle can be modeled with \(AR(2)\) or \(AR(3)\) model
For \(AR(2)\):
\[X_t = b_o + b_1 X_{t-1} + b_2 X_{t-2} + \sigma \epsilon_t\]
Use autoregressive model to model P&C industry combined ratios
Results showed weak mean regression with lag 1 but strong mean regression at lag 2
Model can be used to forecast a few periods into the future and estimate the distribution for those forecasts
VARMAX
Generalized multivariate time series that can handle multiple simultaneous variable and utilize external variables
General Factor Model
- Looks like \(AR(1)\) but with non-normal mean and a moving temporary mean (determined by \(z_{t-1}\))
\[X_t = c + d(Z_{t-1} - X_{t-1}) + \tau \delta_t\]
\(Z_t = a + b \cdot Z_{t-1} + \sigma \epsilon_t\)
\(Z_t\) maybe an unknown or unobservable variable
Neither error term needs to be normal
Complicated to fit this model
- Generalized method of moments or efficient method of moments
26.3.3 Behavioral Modeling
Econometric Modeling
Sit between soft and technical model’s concern for structural insight (soft) and statistical validity (technical)
Same as soft approach:
Where we need large quantity, variety and complexity of data
Recognize human factors
Same as technical approach:
Require mathematical formalism
Tehcnical \(\Rightarrow\) statistical validity
Can be done at an industry level or company level
Industry level can be more detailed
Company level requires maintaining many individual models and their interactions
- Can lead to insight from emergent properties (See ERA 4.2)