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顧客與供應商關係與成本結構
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Column (3) of Table 3 reports the results with full control variables with indicator
variables for industry fixed effects in order to control for the potentially unobserved
industry specific factors that are related to cost behaviors. The results are alike.
Specifically, the coefficient on
∆ln(Sale)
is 0.33973 (
t
-statistic = 26.70), positively
significant at the 0.1% level, which indicates that SG&A costs are positively associated
with the sales revenue. SG&A costs increase 0.34% per 1% increase in sales revenue. The
coefficient on
∆ln(Sale)*Dec
is -0.42537 (
t
-statistic = -17.97), significantly negative at the
0.1% level, which is consistent with the presence of cost stickiness. When customer
concentration (
CC
) is incorporated in the model, the coefficient on my variable of interest,
CC*∆ln(Sale)*Dec
, is 0.92644 (
t
-statistic = 6.28), significantly positive at the 0.1% level.
The result provides strong support for the notion that for companies with more
concentrated customers, SG&A costs are less sticky when sales decrease.
Regarding the control variables, the coefficient on
GDPGrowth
is 0.34035 (
t
-statistic
= 3.67) significantly positive at the 0.1% level, which is consistent with prior literature
that macroeconomic environment is promising; firms may have sales growth and increase
their investment in the production process.
Overall, our results reported in Table 3 cross two specifications show that SG&A cost
behavior reflect a “sticky” pattern; SG&A as a variable component of total costs decreases
less with a sales decrease than it increases with an equivalent sales increase. When
companies with more concentrated customers, SG&A costs are less sticky when sales
decrease. The results support the operations management view that suppliers with
concentrated customer bases achieve better efficiencies by mutual collaboration and
information sharing.