在看一篇文章提到可调节成本，而且分为三类（1）Partial irreversibilities（2）Fixed disruption costs（3）Quadratic adjustment costs
以下是摘自那篇文章的，求有助于理解关于可调节成本的文献。
3.3. Adjustment Costs
The third piece of technology determining the Örmsíactivities are the adjustment costs. There is
a large literature on investment and employment adjustment costs which typically focuses on three
terms, all of which I include in my speciÖcation:
Partial irreversibilities: Labor partial irreversibility, labelled CP
L , derives from per capita
hiring training and Öring costs, and is denominated as a fraction of annual wages (at the standard
working week). For simplicity I assume these costs apply equally to gross hiring and gross Öring
of workers.
19 Capital partial irreversibilities arise from resale losses due to transactions costs, the
market for lemons phenomenon and the physical costs of resale. The resale loss of capital is labelled
CP
K and is denominated as a fraction of the relative purchase price of capital.
Fixed disruption costs: When new workers are added into the production process and new
capital is installed some downtime may result, involving a Öxed cost loss of output. For example,
adding workers may require Öxed costs of advertising, interviewing and training, or the factory may
need to close for a few days while a capital reÖt is occurring. I model these Öxed costs as CF
L and
CF
K for hiring/Öring and investment respectively, both denominated as fractions of annual sales.
Quadratic adjustment costs: The costs of hiring/Öring and investment may also be related to
the rate of adjustment due to higher costs for more rapid changes, where CQ
L L(
E
L )2 are the quadratic
hiring/Öring costs and E denotes gross hiring/Öring, and CQ
KK(
I
K)2 are the quadratic investment
costs and I denotes gross investment.
The combination of all adjustment costs is given by the adjustment cost function:
C(A;K;L;H; I;E; pK
t ) = 52w(40)CP
L (E+ + E ) + (I+   (1   CP
K)I ) +

CF
L 1fE=0g + CF
K1fI=0g


S(A;K;L;H) + CQ
L L(
E
L
)
2
+ CQ
KK(
I
K)
2
where E+ (I+) and E  (I ) are the absolute values of positive and negative hiring (investment)
respectively, and 1fE=0g and 1fI=0g are indicator functions which equal 1 if true and 0 otherwise.
New labor and capital take one period to enter production due to time to build. This assumption is
made to allow me to pre-optimize hours (explained in section (3.5) below), but is unlikely to play a
major role in the simulations given the monthly periodicity. At the end of each period there is labor
attrition and capital depreciation proportionate to L and K respectively.