METHODS
,Data structure
effect
Fxed
>
->
Data
clearing
,variable generation
The value generatedis
observation
for each specific
group level statistics ,
calculation
involving multiple
observations
(Sum up/average)
Collapsing variables
Collapsing variables :
Combining multiple categories or observations
a) collapsing categories Primary Is lower education
: secondary
,
Bachelor, master >
->
higher education
, b) Collapsing observations : Summane data across time or
groups
=> E Individual wages >
-
for firm
.
:
g average wage a
Monthly sales -
yearly sales
2) Collapsing dummy variables
=> E
g
: owns cars owns bike >
-
owns vehicles
any
.
,
sum the
monthly pop
、 of the combined observations
that has the same
&
country year
,Data structure
effect
Fxed
>
->
Data
clearing
,variable generation
The value generatedis
observation
for each specific
group level statistics ,
calculation
involving multiple
observations
(Sum up/average)
Collapsing variables
Collapsing variables :
Combining multiple categories or observations
a) collapsing categories Primary Is lower education
: secondary
,
Bachelor, master >
->
higher education
, b) Collapsing observations : Summane data across time or
groups
=> E Individual wages >
-
for firm
.
:
g average wage a
Monthly sales -
yearly sales
2) Collapsing dummy variables
=> E
g
: owns cars owns bike >
-
owns vehicles
any
.
,
sum the
monthly pop
、 of the combined observations
that has the same
&
country year
