one time changes and common types
need to adjust for one time changes
direct and indirect effects
Rate increase would result loss in prem due to changes in retention/close ratios
Indemnity benefit increase might cause more injured workers filing claims and workers staying OOO longer
-indirect are difficult to quantify and are not usually incorporated into adjustments
3 ways to calc effect of coverage change on losses
*WC benefit level changes
2 methods to on-level
OLF
=current cumulative rate level index/(weighted average cumulative rate level index for that time period)
continuous changes and examples
changes that occur gradually over time like changes in MOV and socio-economic trends
adjusting hist data for continuous changes ensures
that data reflects MOB and levels of social and economic inflation expected in future period
data used for trending
why use most recent data for trending?
reduce duration and thus uncertainty in forecast
premium data to use
loss data to use
using calendar period data for loss assumes
BOB is not significantly growing or shrinking since mismatch of losses and exposures
-for short tailed, this is likely to be reasonable, but not long tailed since bigger distance between when exposures are written and losses are paid or reported
adv to using paid data
paid data is not subject to changes in case reserving practices
adv to using rptd data
incorporates more recent info since case reserves provide info you might expect to eventually see in paid
trends for layers of loss
2 reasons excess severity trends are greater than total or basic limits severity trends when trend is positive
why do we need trend periods?
need to obtain range of dates for which we expect new rates to be in effect so we can project avg prem and PPs to appropriate levels
2 assumptions normally made when selecting trend periods
2 step trends
2 ways to perfom first step of 2 step trending
current trend factor = latest avg WP @ curr/ hist avg EP @ curr
exposure trends
-for LOBS with inflation-sensitive EBs such as payroll for WC, exposures can change over time because of inflation and applying exposure trend may be appropriate in RM analysis
expense trends
inflationary trends also impact expense levels
If the data used in both determining and applying the trend is not adjusted for large events & anomalies
it may be difficult to choose an appropriate trend rate and we may over or under project future values