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Nicolò Gnocato, Concetta Rondinelli, Granular Sources of the Italian Business Cycle
1. Granular Sources of the
Italian Business Cycle
Nicolò Gnocato Concetta Rondinelli
Banca d’Italia
2. Aim of this Research
A recent stream of literature (Gabaix, 2011; Carvalho and Gabaix, 2013;
di Giovanni et al., 2014) has investigated the granular sources of the business
cycle, i.e. the hypothesis according to which a small group of firms in the
economy, usually the largest, drive aggregate dynamics;
3. Aim of this Research
A recent stream of literature (Gabaix, 2011; Carvalho and Gabaix, 2013;
di Giovanni et al., 2014) has investigated the granular sources of the business
cycle, i.e. the hypothesis according to which a small group of firms in the
economy, usually the largest, drive aggregate dynamics;
We test this hypothesis on Italian firms’ microdata (retrieved from the Cerved
database);
4. Aim of this Research
A recent stream of literature (Gabaix, 2011; Carvalho and Gabaix, 2013;
di Giovanni et al., 2014) has investigated the granular sources of the business
cycle, i.e. the hypothesis according to which a small group of firms in the
economy, usually the largest, drive aggregate dynamics;
We test this hypothesis on Italian firms’ microdata (retrieved from the Cerved
database);
The Italian manufacturing productive system has two features of interest to this
regard:
5. Aim of this Research
A recent stream of literature (Gabaix, 2011; Carvalho and Gabaix, 2013;
di Giovanni et al., 2014) has investigated the granular sources of the business
cycle, i.e. the hypothesis according to which a small group of firms in the
economy, usually the largest, drive aggregate dynamics;
We test this hypothesis on Italian firms’ microdata (retrieved from the Cerved
database);
The Italian manufacturing productive system has two features of interest to this
regard:
1. the small size of businesses, on one hand, which would in principle weaken
the granular hypothesis,
6. Aim of this Research
A recent stream of literature (Gabaix, 2011; Carvalho and Gabaix, 2013;
di Giovanni et al., 2014) has investigated the granular sources of the business
cycle, i.e. the hypothesis according to which a small group of firms in the
economy, usually the largest, drive aggregate dynamics;
We test this hypothesis on Italian firms’ microdata (retrieved from the Cerved
database);
The Italian manufacturing productive system has two features of interest to this
regard:
1. the small size of businesses, on one hand, which would in principle weaken
the granular hypothesis,
2. the strong geographical firms’ agglomeration by sector of activity
(districts), which, on the other hand, could amplify the idiosyncratic
sources of aggregate fluctuations.
7. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
8. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
10. Introduction
Do firm-level dynamics have an impact on aggregate fluctuations?
The predominant tradition in macroeconomics has long assumed that
idiosyncratic shocks to individual firms average out and thus have negligible
effects at the aggregate level (Lucas, 1977).
11. Introduction
Do firm-level dynamics have an impact on aggregate fluctuations?
The predominant tradition in macroeconomics has long assumed that
idiosyncratic shocks to individual firms average out and thus have negligible
effects at the aggregate level (Lucas, 1977).
Two recent strands of literature have started challenging this perspective:
12. Introduction
Do firm-level dynamics have an impact on aggregate fluctuations?
The predominant tradition in macroeconomics has long assumed that
idiosyncratic shocks to individual firms average out and thus have negligible
effects at the aggregate level (Lucas, 1977).
Two recent strands of literature have started challenging this perspective:
a. If the firm size distribution is sufficiently fat-tailed (i.e. the
economy is ”granular”), idiosyncratic shocks to individual
(large) firms will not average out and, instead, lead to
movements in the aggregates (Gabaix, 2011);
13. Introduction
Do firm-level dynamics have an impact on aggregate fluctuations?
The predominant tradition in macroeconomics has long assumed that
idiosyncratic shocks to individual firms average out and thus have negligible
effects at the aggregate level (Lucas, 1977).
Two recent strands of literature have started challenging this perspective:
a. If the firm size distribution is sufficiently fat-tailed (i.e. the
economy is ”granular”), idiosyncratic shocks to individual
(large) firms will not average out and, instead, lead to
movements in the aggregates (Gabaix, 2011);
b. Idiosyncratic shocks to a single sector/firm can have sizeable
aggregate effects if the secotor/firm is interconnected with
others in the economy through input linkages: these linkages
propagate microeconomic shocks leading to positive
endogenous comovement (Acemoglu et al., 2012).
14. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
16. Conceptual Framework
Consider an economy populated by n competitive firms, producing intermediate
and final goods using capital, labor and other intermediate inputs sourced from
one another;
17. Conceptual Framework
Consider an economy populated by n competitive firms, producing intermediate
and final goods using capital, labor and other intermediate inputs sourced from
one another;
If a Hicks-neutral, idosyncratic productivity shock ˜ωi = dωi /ωi hits firm i then,
according to Hulten (1978), the corresponding shock to aggregate TFP is given
by
˜Ω =
dΩ
Ω
=
n
i=1
Qi
Y
˜ωi
where Qi = firm i’s gross production value, Y = nominal aggregate value
added, and Qi /Y = “Domar” weight ( i (Qi /Y ) ≥ 1);
i.e. a change in firm i’s efficiency creates extra output which
can increase both aggregate value added and intermediate
goods’ supplies.
18. If we allow firm-level TFP shocks to be cross-sectionally correlated (Carvalho
and Gabaix, 2013; di Giovanni et al., 2014) we have
σ2
˜Ωt
= σ2
Ft
=
i,j=1,...,n
Qit
Yt
Qjt
Yt
ρij σi σj
where ρij =
cov(˜ωi ,˜ωj )
σi σj
, σi = var (˜ωi );
19. If we allow firm-level TFP shocks to be cross-sectionally correlated (Carvalho
and Gabaix, 2013; di Giovanni et al., 2014) we have
σ2
˜Ωt
= σ2
Ft
=
i,j=1,...,n
Qit
Yt
Qjt
Yt
ρij σi σj
where ρij =
cov(˜ωi ,˜ωj )
σi σj
, σi = var (˜ωi );
σ2
Ft
can accordingly be decomposed as follows
σ2
Ft
=
i,j=1,...,n
Qit
Yt
Qjt
Yt
ρij σi σj =
=
n
i=1
Qit
Yt
2
σ2
i
DIRECT
+
i=j j
Qit
Yt
Qjt
Yt
cov ˜ωi , ˜ωj
LINK
21. Conceptual Framework
Variance Contribution to Aggregate TFP Shocks (direct effect)
n
i=1
Qit
Yt
2
σ2
i
When the distribution of firm size is sufficiently fat-tailed (i.e. the economy is
“granular”), idiosyncratic shocks to individual firms do not wash out at the
aggregate level, because shocks to large firms do not cancel out with shocks to
smaller units (Gabaix, 2011);
22. Conceptual Framework
Variance Contribution to Aggregate TFP Shocks (direct effect)
n
i=1
Qit
Yt
2
σ2
i
When the distribution of firm size is sufficiently fat-tailed (i.e. the economy is
“granular”), idiosyncratic shocks to individual firms do not wash out at the
aggregate level, because shocks to large firms do not cancel out with shocks to
smaller units (Gabaix, 2011);
Simple illustration: uncorrelated shocks (cov ˜ωi , ˜ωj = 0 ∀i, j) and
σ2
i = σ2 ∀i. Then
σ2
Ft
= σ2
n
i=1
Qit
Yt
2
= σ2
× Ht
where Ht = n
i=1 (Qit /Yt )2
denotes the Herfindahl index of the economy.
23. Conceptual Framework
Variance Contribution to Aggregate TFP Shocks (direct effect)
n
i=1
Qit
Yt
2
σ2
i
When the distribution of firm size is sufficiently fat-tailed (i.e. the economy is
“granular”), idiosyncratic shocks to individual firms do not wash out at the
aggregate level, because shocks to large firms do not cancel out with shocks to
smaller units (Gabaix, 2011);
Simple illustration: uncorrelated shocks (cov ˜ωi , ˜ωj = 0 ∀i, j) and
σ2
i = σ2 ∀i. Then
σ2
Ft
= σ2
n
i=1
Qit
Yt
2
= σ2
× Ht
where Ht = n
i=1 (Qit /Yt )2
denotes the Herfindahl index of the economy.
The more fat-tailed the firm-size distribution, the larger Ht and the
greater the aggregate TFP volatility originating from idiosyncratic shocks;
24. Conceptual Framework
Variance Contribution to Aggregate TFP Shocks (direct effect)
n
i=1
Qit
Yt
2
σ2
i
When the distribution of firm size is sufficiently fat-tailed (i.e. the economy is
“granular”), idiosyncratic shocks to individual firms do not wash out at the
aggregate level, because shocks to large firms do not cancel out with shocks to
smaller units (Gabaix, 2011);
Simple illustration: uncorrelated shocks (cov ˜ωi , ˜ωj = 0 ∀i, j) and
σ2
i = σ2 ∀i. Then
σ2
Ft
= σ2
n
i=1
Qit
Yt
2
= σ2
× Ht
where Ht = n
i=1 (Qit /Yt )2
denotes the Herfindahl index of the economy.
The more fat-tailed the firm-size distribution, the larger Ht and the
greater the aggregate TFP volatility originating from idiosyncratic shocks;
Opposite extreme: economic activity symmetrically distributed across
firms (Qit = Yt /n)
σFt = σ/
√
n
the contribution of idiosyncratic shocks to aggregate volatility decays
rapidly as n increases.
26. Conceptual Framework
Covariance Contribution to Aggregate TFP Shocks (linkages effect)
i=j j
Qit
Yt
Qjt
Yt
cov ˜ωi , ˜ωj
The covariance term captures the contribution of comovement across firms in
explaining aggregate volatility;
27. Conceptual Framework
Covariance Contribution to Aggregate TFP Shocks (linkages effect)
i=j j
Qit
Yt
Qjt
Yt
cov ˜ωi , ˜ωj
The covariance term captures the contribution of comovement across firms in
explaining aggregate volatility;
Cross-firm correlations can arise, for instance, from input-output linkages and/or
local labor market interactions;
28. Conceptual Framework
Covariance Contribution to Aggregate TFP Shocks (linkages effect)
i=j j
Qit
Yt
Qjt
Yt
cov ˜ωi , ˜ωj
The covariance term captures the contribution of comovement across firms in
explaining aggregate volatility;
Cross-firm correlations can arise, for instance, from input-output linkages and/or
local labor market interactions;
As shown by Acemoglu et al. (2012), idiosyncratic shocks to single sectors/firms
can be propagated through input-output linkages, leading to positive
endogenous comovement and, in turn, to aggregate fluctuations.
29. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
31. Empirical Implementation
Granular Residual
TFP growth rate
git = ωit − ωi,t−1
where ωit is the log of firm-level productivity: ωit = yit − ˆβl lit − ˆβk kit , with ˆβl
and ˆβk estimated through the methodology proposed by Ackerberg et al. (2015);
32. Empirical Implementation
Granular Residual
TFP growth rate
git = ωit − ωi,t−1
where ωit is the log of firm-level productivity: ωit = yit − ˆβl lit − ˆβk kit , with ˆβl
and ˆβk estimated through the methodology proposed by Ackerberg et al. (2015);
The cross-section of git ’s in a given year is regressed on a set of sector fixed
effects
git = δjt + eit
and the residual eit is retained as the firm-specific shock;
33. Empirical Implementation
Granular Residual
TFP growth rate
git = ωit − ωi,t−1
where ωit is the log of firm-level productivity: ωit = yit − ˆβl lit − ˆβk kit , with ˆβl
and ˆβk estimated through the methodology proposed by Ackerberg et al. (2015);
The cross-section of git ’s in a given year is regressed on a set of sector fixed
effects
git = δjt + eit
and the residual eit is retained as the firm-specific shock;
Define the Granular Residual as the sum of idiosyncratic shocks, eit , weighted by
size (Gabaix, 2011)
Et ≡
i
Yi,t−1
Yt−1
eit
34. Empirical Implementation
Granular Residual
TFP growth rate
git = ωit − ωi,t−1
where ωit is the log of firm-level productivity: ωit = yit − ˆβl lit − ˆβk kit , with ˆβl
and ˆβk estimated through the methodology proposed by Ackerberg et al. (2015);
The cross-section of git ’s in a given year is regressed on a set of sector fixed
effects
git = δjt + eit
and the residual eit is retained as the firm-specific shock;
Define the Granular Residual as the sum of idiosyncratic shocks, eit , weighted by
size (Gabaix, 2011)
Et ≡
i
Yi,t−1
Yt−1
eit
Similarly, for common-sector shocks, we define
∆t ≡
j
Yj,t−1
Yt−1
δjt
where Yj = i∈j Yi
35. Empirical Implementation
Granular Residual
TFP growth rate
git = ωit − ωi,t−1
where ωit is the log of firm-level productivity: ωit = yit − ˆβl lit − ˆβk kit , with ˆβl
and ˆβk estimated through the methodology proposed by Ackerberg et al. (2015);
The cross-section of git ’s in a given year is regressed on a set of sector fixed
effects
git = δjt + eit
and the residual eit is retained as the firm-specific shock;
Define the Granular Residual as the sum of idiosyncratic shocks, eit , weighted by
size (Gabaix, 2011)
Et ≡
i
Yi,t−1
Yt−1
eit
Similarly, for common-sector shocks, we define
∆t ≡
j
Yj,t−1
Yt−1
δjt
where Yj = i∈j Yi
NB: we use value added weights here since the TFP measure is value added
based (Domar weights used if gross output based).
37. Empirical Implementation
Contributions to Aggregate TFP Volatility
Aggregate TFP growth at the intensive margin can be approximated, to a first
order, by
i
Yi,t−1
Yt−1
git =
j
Yj,t−1
Yt−1
δjt +
i
Yi,t−1
Yt−1
eit
38. Empirical Implementation
Contributions to Aggregate TFP Volatility
Aggregate TFP growth at the intensive margin can be approximated, to a first
order, by
i
Yi,t−1
Yt−1
git =
j
Yj,t−1
Yt−1
δjt +
i
Yi,t−1
Yt−1
eit
For a given time period τ, weights are fixed at their τ − 1 values and combined
with shock from period t (Carvalho and Gabaix, 2013; di Giovanni et al., 2014)
i
Yi,τ−1
Yτ−1
git =
j
Yj,τ−1
Yτ−1
δjt +
i
Yi,τ−1
Yτ−1
eit
39. Empirical Implementation
Contributions to Aggregate TFP Volatility
Aggregate TFP growth at the intensive margin can be approximated, to a first
order, by
i
Yi,t−1
Yt−1
git =
j
Yj,t−1
Yt−1
δjt +
i
Yi,t−1
Yt−1
eit
For a given time period τ, weights are fixed at their τ − 1 values and combined
with shock from period t (Carvalho and Gabaix, 2013; di Giovanni et al., 2014)
i
Yi,τ−1
Yτ−1
git =
j
Yj,τ−1
Yτ−1
δjt +
i
Yi,τ−1
Yτ−1
eit
Variance of aggregate TFP growth
σ2
Ωτ
= σ2
∆τ
+ σ2
Fτ
+ COVτ
σ2
∆τ
= Var
j
Yj,τ−1
Yτ−1
δjt
σ2
Fτ
= Var
i
Yi,τ−1
Yτ−1
eit
COVτ = Cov
j
Yj,τ−1
Yτ−1
δjt ,
i
Yi,τ−1
Yτ−1
eit
40. e.g., for each τ = 1, ..., T, σ2
Fτ
is the sample variance of the T realizations
(t = 1, ..., T) of i
Qi,τ−1
Yτ−1
eit (Carvalho and Gabaix, 2013; di Giovanni
et al., 2014)
σ2
Fτ=1
= Var
i
Yi0
Y0
eit
σ2
Fτ=2
= Var
i
Yi1
Y1
eit
...
41. e.g., for each τ = 1, ..., T, σ2
Fτ
is the sample variance of the T realizations
(t = 1, ..., T) of i
Qi,τ−1
Yτ−1
eit (Carvalho and Gabaix, 2013; di Giovanni
et al., 2014)
σ2
Fτ=1
= Var
i
Yi0
Y0
eit
σ2
Fτ=2
= Var
i
Yi1
Y1
eit
...
We use the standard deviation as our measure of volatility, and present the
results in terms of relative standard deviations σFτ /σΩτ and σ∆τ /σΩτ when
discussing contributions to aggregate volatility σΩτ .
43. Empirical Implementation
Channels for Firms’ Contributions
Recall that firm-specific volatility σ2
Fτ
can be decomposed into a variance (or
direct) and a covariance (or linkages) contribution
σ2
Fτ
= Var
i
Yi,τ−1
Yτ−1
eit
=
i
Yi,τ−1
Yτ−1
2
Var (eit )
DIRECT
+
i=j j
Yi,τ−1
Yτ−1
Yj,τ−1
Yτ−1
Cov eit , ejt
LINK
44. Empirical Implementation
Channels for Firms’ Contributions
Recall that firm-specific volatility σ2
Fτ
can be decomposed into a variance (or
direct) and a covariance (or linkages) contribution
σ2
Fτ
= Var
i
Yi,τ−1
Yτ−1
eit
=
i
Yi,τ−1
Yτ−1
2
Var (eit )
DIRECT
+
i=j j
Yi,τ−1
Yτ−1
Yj,τ−1
Yτ−1
Cov eit , ejt
LINK
We look at relative standard deviations
√
DIRECT/σFτ and
√
LINK/σFτ to
assess the relative contributions of the direct and linkages channels respectively.
45. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
46. Data
Italian limited liability companies’ balance sheets data from CERVED merged
with info on number of employees from INPS;
47. Data
Italian limited liability companies’ balance sheets data from CERVED merged
with info on number of employees from INPS;
Real Capital Stock constructed by means of a Perpetual Inventory Method
(PIM), correcting initial book values and investments for re-evaluation of assets
Kt = (1 − δ)Kt−1 + It
48. Data
Italian limited liability companies’ balance sheets data from CERVED merged
with info on number of employees from INPS;
Real Capital Stock constructed by means of a Perpetual Inventory Method
(PIM), correcting initial book values and investments for re-evaluation of assets
Kt = (1 − δ)Kt−1 + It
Firm-level TFP estimated with the Ackerberg et al. (2015) methodology;
49. Data
Italian limited liability companies’ balance sheets data from CERVED merged
with info on number of employees from INPS;
Real Capital Stock constructed by means of a Perpetual Inventory Method
(PIM), correcting initial book values and investments for re-evaluation of assets
Kt = (1 − δ)Kt−1 + It
Firm-level TFP estimated with the Ackerberg et al. (2015) methodology;
Final sample:
50. Data
Italian limited liability companies’ balance sheets data from CERVED merged
with info on number of employees from INPS;
Real Capital Stock constructed by means of a Perpetual Inventory Method
(PIM), correcting initial book values and investments for re-evaluation of assets
Kt = (1 − δ)Kt−1 + It
Firm-level TFP estimated with the Ackerberg et al. (2015) methodology;
Final sample:
1. Period: 1999–2014;
2. Firms with gaps in relevant variables are excluded from the analysis;
51. Data
Italian limited liability companies’ balance sheets data from CERVED merged
with info on number of employees from INPS;
Real Capital Stock constructed by means of a Perpetual Inventory Method
(PIM), correcting initial book values and investments for re-evaluation of assets
Kt = (1 − δ)Kt−1 + It
Firm-level TFP estimated with the Ackerberg et al. (2015) methodology;
Final sample:
1. Period: 1999–2014;
2. Firms with gaps in relevant variables are excluded from the analysis;
3. Growth rate of TFP, git , winsorized at 5%.
52. Preliminary Statistics
Summary Statistics of Main Variables
Observations Mean St. Dev.
Value Added 3,597,015 1267.33 25335.86
Employees 3,597,015 22.38 287.54
Capital Stock 3,597,015 1344.78 36252.45
TFP 3,597,015 33.34 72.90
Value Added, Capital Stock and TFP: constant 2010 prices (thousand
euros). Employees: average number of workers employed across the year
according to INPS.
55. Preliminary Statistics
Firm-level Volatility by Size
St.Dev. Whole Economy Manufacturing
Average 0.2938 0.2709
Size Percentile
0–20 0.3729 0.3441
21–40 0.3211 0.2837
41–60 0.2843 0.2582
61–80 0.2576 0.2407
81–100 0.2298 0.2249
Larger firms have, on average, lower TFP volatility;
Direct effect ( n
i=1(Yit /Yt )2σ2
i ) potentially dampened as to (Yit /Yt ) ↑
corresponds, on average, σi ↓.
56. Preliminary Statistics
Summary Statictics and Correlations of Shocks
Obs. Mean St.Dev. Correlation
Actual (git) 3,178,447 -0.0201 0.3096 1.0000
Firm-specific (eit) 3,178,447 0.0000 0.3056 0.9870
Common (δst) 1,140 -0.0202 0.0496 0.1608
57. Preliminary Statistics
Summary Statictics and Correlations of Shocks
Obs. Mean St.Dev. Correlation
Actual (git) 3,178,447 -0.0201 0.3096 1.0000
Firm-specific (eit) 3,178,447 0.0000 0.3056 0.9870
Common (δst) 1,140 -0.0202 0.0496 0.1608
Simply observing high correlation, at firm-level, between git and eit does not
automatically mean that idiosyncratic shocks matter more at the aggregate level
(they could average out);
58. Preliminary Statistics
Summary Statictics and Correlations of Shocks
Obs. Mean St.Dev. Correlation
Actual (git) 3,178,447 -0.0201 0.3096 1.0000
Firm-specific (eit) 3,178,447 0.0000 0.3056 0.9870
Common (δst) 1,140 -0.0202 0.0496 0.1608
Simply observing high correlation, at firm-level, between git and eit does not
automatically mean that idiosyncratic shocks matter more at the aggregate level
(they could average out);
On the other hand, observing that eit ’s average is 0, does not automatically
mean that idiosyncratic shocks do not matter at the aggregate level;
59. Preliminary Statistics
Summary Statictics and Correlations of Shocks
Obs. Mean St.Dev. Correlation
Actual (git) 3,178,447 -0.0201 0.3096 1.0000
Firm-specific (eit) 3,178,447 0.0000 0.3056 0.9870
Common (δst) 1,140 -0.0202 0.0496 0.1608
Simply observing high correlation, at firm-level, between git and eit does not
automatically mean that idiosyncratic shocks matter more at the aggregate level
(they could average out);
On the other hand, observing that eit ’s average is 0, does not automatically
mean that idiosyncratic shocks do not matter at the aggregate level;
To answer whether they matter or not, we have to account for the firm-size
distribution (through weighted aggregation).
61. Preliminary Statistics
Aggregate TFP Growth
(a) Whole Economy (b) Manufacturing
The CERVED (sub)sample seems to do a good job in following TFP dynamics
of aggregate data, especially for manufacturing; also recall that:
62. Preliminary Statistics
Aggregate TFP Growth
(a) Whole Economy (b) Manufacturing
The CERVED (sub)sample seems to do a good job in following TFP dynamics
of aggregate data, especially for manufacturing; also recall that:
1. CERVED only includes limited liability companies;
63. Preliminary Statistics
Aggregate TFP Growth
(a) Whole Economy (b) Manufacturing
The CERVED (sub)sample seems to do a good job in following TFP dynamics
of aggregate data, especially for manufacturing; also recall that:
1. CERVED only includes limited liability companies;
2. Firms with gaps in relevant variables are excluded from the analysis;
64. Preliminary Statistics
Aggregate TFP Growth
(a) Whole Economy (b) Manufacturing
The CERVED (sub)sample seems to do a good job in following TFP dynamics
of aggregate data, especially for manufacturing; also recall that:
1. CERVED only includes limited liability companies;
2. Firms with gaps in relevant variables are excluded from the analysis;
3. We are focusing only on the intensive margin of firm TFP growth.
65. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
68. Volatility of Aggregate TFP Growth and its Components
A. Whole Economy
σ2
Ωτ
= σ2
∆τ
+ σ2
Fτ
+ COVτ
(a) Aggregate (b) Common-Sector (c) Idiosyncratic
69. Volatility of Aggregate TFP Growth and its Components
B. Manufacturing
σ2
Ωτ
= σ2
∆τ
+ σ2
Fτ
+ COVτ
(a) Aggregate (b) Common-Sector (c) Idiosyncratic
70. Aggregate Impact of Firm-Specific Shocks on Aggregate
Volatility
Whole Economy Manufacturing
St.Dev. Relative SD St.Dev. Relative SD
A. 2000–2014
Actual (¯σΩ) 0.0076 1.0000 0.0261 1.0000
Firm-specific (¯σF ) 0.0032 0.4203 0.0079 0.3030
Common-Sector (¯σ∆) 0.0061 0.8090 0.0215 0.8271
B. 2000–2007
Actual (¯σΩ) 0.0071 1.0000 0.0233 1.0000
Firm-specific (¯σF ) 0.0031 0.4394 0.0074 0.3156
Common-Sector (¯σ∆) 0.0054 0.7644 0.0181 0.7776
C. 2008–2014
Actual (¯σΩ) 0.0082 1.0000 0.0294 1.0000
Firm-specific (¯σF ) 0.0032 0.3986 0.0084 0.2886
Common-Sector (¯σ∆) 0.0069 0.8600 0.0255 0.8836
Averages ¯σΩ, ¯σF , and ¯σ∆ over different periods — ¯σΩ = 1
T τ σΩτ , ¯σF = 1
T τ σFτ ,
¯σ∆ = 1
T τ σ∆τ — and in relative terms w.r.t. ¯σΩ — 1
T τ
σFτ
σΩτ
, 1
T τ
σ∆τ
σΩτ
.
71. Contributions to firm-specific volatility
σ2
Fτ
= Var
i
Yi,τ−1
Yτ−1
eit
=
i
Yi,τ−1
Yτ−1
2
Var (eit )
DIRECT
+
i=j j
Yi,τ−1
Yτ−1
Yj,τ−1
Yτ−1
Cov eit , ejt
LINK
(a) Whole Economy (b) Manufacturing
72. Contributions to firm-specific volatility
Whole Economy Manufacturing
St.Dev. Relative SD St.Dev. Relative SD
A. 2000–2014
Firm-specific 0.0032 1.0000 0.0079 1.0000
Direct 0.0018 0.5894 0.0029 0.3709
Linkages 0.0026 0.7997 0.0073 0.9282
B. 2000–2007
Firm-specific 0.0031 1.0000 0.0074 1.0000
Direct 0.0017 0.5745 0.0027 0.3652
Linkages 0.0026 0.8091 0.0069 0.9305
C. 2008–2014
Firm-specific 0.0032 1.0000 0.0084 1.0000
Direct 0.0019 0.6064 0.0031 0.3775
Linkages 0.0026 0.7889 0.0078 0.9255
73. Direct Effect’s Contribution
Possible exercise: construct a simple counterfactual by artificially assuming that
all firms are of equal size (i.e. Yi,τ−1/Yτ−1 = 1/Nτ−1 ∀i).
2000–2014 2000–2007 2008–2014
St.Dev. Ratio St.Dev. Ratio St.Dev. Ratio
Direct 0.0018 1.00 0.0017 1.00 0.0019 1.00
Counterfactual 0.0007 2.78 0.0007 2.45 0.0006 3.16
Std.Dev. of counterfactual about 3 times smaller than actual direct component,
on average;
Evidence that the presence of a fat right tail in the firm size distribution does
matter when considering the direct contribution of firm-specific shocks to
aggregate fluctuations (but less than what found for, e.g., France due to smaller
average firm size in Italy).
74. Direct Effect’s Contribution
Other exercise: sectoral decomposition of the overall-economy direct
component; sector r’s direct component
DIRECTrτ =
i∈r
Yi,τ−1
Yτ−1
2
Var (eit )
so that DIRECTτ = r DIRECTrτ ;
More concentrated sectors (i.e. with higher Hrτ = i∈r Yi,τ−1/Yτ−1
2
)
display larger direct volatilities.
(a) 2001 (b) 2006 (c) 2011
Strongly positive correlation, but less than perfect because firm-level variances
differ both within and between sectors.
75. Firm Linkages’ Contribution
Linkages Volatility and Input-Output Intensity
Question: does the comovement captured by the LINK component arise from
input-output linkages?
76. Firm Linkages’ Contribution
Linkages Volatility and Input-Output Intensity
Question: does the comovement captured by the LINK component arise from
input-output linkages?
We use data on sector pairs from Input-Output (IO) tables by the OECD and
follow di Giovanni et al. (2014) decomposing the LINK component across sector
pairs
LINKrsτ =
i∈r j∈s
Yi,τ−1
Yτ−1
Yj,τ−1
Yτ−1
Cov eit , ejt
so that LINKτ = r s LINKrsτ .
77. Firm Linkages’ Contribution
Linkages Volatility and Input-Output Intensity
Question: does the comovement captured by the LINK component arise from
input-output linkages?
We use data on sector pairs from Input-Output (IO) tables by the OECD and
follow di Giovanni et al. (2014) decomposing the LINK component across sector
pairs
LINKrsτ =
i∈r j∈s
Yi,τ−1
Yτ−1
Yj,τ−1
Yτ−1
Cov eit , ejt
so that LINKτ = r s LINKrsτ .
Define mean intensity of IO linkages between sectors r and s as
IOrs =
1
2
[(1 − λr ) ρrs + (1 − λs ) ρsr ]
where λr = share of value added in sector r’s total output & ρrs = share of
inputs sourced domestically from sector s in sector r’s total domestic spending
on intermediates.
78. Firm Linkages’ Contribution
Linkages Volatility and Input-Output Intensity
Question: does the comovement captured by the LINK component arise from
input-output linkages?
We use data on sector pairs from Input-Output (IO) tables by the OECD and
follow di Giovanni et al. (2014) decomposing the LINK component across sector
pairs
LINKrsτ =
i∈r j∈s
Yi,τ−1
Yτ−1
Yj,τ−1
Yτ−1
Cov eit , ejt
so that LINKτ = r s LINKrsτ .
Define mean intensity of IO linkages between sectors r and s as
IOrs =
1
2
[(1 − λr ) ρrs + (1 − λs ) ρsr ]
where λr = share of value added in sector r’s total output & ρrs = share of
inputs sourced domestically from sector s in sector r’s total domestic spending
on intermediates.
Expect positive correlation between LINKrs and IOrs if comovement arises from
input-output linkages.
79. Firm Linkages’ Contribution
Linkages Volatility and Labor Market Concentration
Labor market interactions provide another potential cause of comovement
between firms;
80. Firm Linkages’ Contribution
Linkages Volatility and Labor Market Concentration
Labor market interactions provide another potential cause of comovement
between firms;
Proxy the extent of labor market pooling occurring between each pair of sectors
with a pseudo-Herfindahl index of concentration of economic activity across
Italian provinces
Hrs =
P
p=1
˜z2
p
with:
˜z2
p =
( i∈r∩p Li )( i∈s∩p Li )
( i∈r Li )( i∈s Li )
where Li = workers employed by firm i, p indexes Italian provinces, r and s
index sectors; in order to measure pooling between sectors r and s (not only
within either one of them), omit squared terms and keep only interaction terms
from z2
p = i∈r,s∩p Li
i∈r,s Li
2
;
81. Firm Linkages’ Contribution
Linkages Volatility and Labor Market Concentration
Labor market interactions provide another potential cause of comovement
between firms;
Proxy the extent of labor market pooling occurring between each pair of sectors
with a pseudo-Herfindahl index of concentration of economic activity across
Italian provinces
Hrs =
P
p=1
˜z2
p
with:
˜z2
p =
( i∈r∩p Li )( i∈s∩p Li )
( i∈r Li )( i∈s Li )
where Li = workers employed by firm i, p indexes Italian provinces, r and s
index sectors; in order to measure pooling between sectors r and s (not only
within either one of them), omit squared terms and keep only interaction terms
from z2
p = i∈r,s∩p Li
i∈r,s Li
2
;
The resulting pseudo-Herfindahl measure ranges between 1/P and 1, and avoids
the potential issue of capturing high concentration in only one of the two
sectors.
82. Firm Linkages’ Contribution
Results
More interconnected pairs of sectors (as measured from OECD IO tables, or labor
market concentration) significantly display higher linkages volatilities.
Pairwise correlations positive and highly significant for both mean IO intensity
and labor market interaction (more pronounced for the former);
LINKrs 2001 2006 2011
IOrs 0.4788∗∗∗ 0.4273∗∗∗ 0.3684∗∗∗
Hrs 0.2861∗∗∗ 0.2170∗∗∗ 0.3329∗∗∗
Partial contributions (standardized beta coefficients) coherently display higher
relevance and significance for mean IO intensity than for labor market pooling.
LINKrs 2001 2006 2011
IOrs 0.432∗∗∗ 0.400∗∗∗ 0.284∗∗∗
Hrs 0.132∗∗∗ 0.078∗ 0.228∗∗∗
N 528 528 528
R2 0.244 0.188 0.181
adj. R2 0.242 0.185 0.178
83. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
84. Extensions and Robustness
1. LP shocks in place of TFP shocks:
isolate idiosyncratic shocks eit from
∆lpit = δst + eit
where lpit = ln (Yit /Lit ) and we also control for the growth rate in the capital
stock per employee ∆klit = ∆ln(Kit /Lit )
∆lpit = ∆klit + uit
∆lpit = uit
∆lpit = δst + eit
this should give eit (TFP-based) highly correlated with eit .
I. Productivity Growth
TFP LP LP’
Corr. with TFP growth 1.0000 0.9203 0.9881
II. Idiosyncratic Component
eit eit eit
Corr. with Idiosyncratic TFP growth 1.0000 0.9189 0.9881
85. Extensions and Robustness
1. LP based idiosyncratic shocks (controlling for K per employee)
Whole Economy Manufacturing
St.Dev. Relative SD St.Dev. Relative SD
A. 2000–2014
Actual (¯σΩ) 0.0075 1.0000 0.0262 1.0000
Firm-specific (¯σF ) 0.0031 0.4094 0.0078 0.3007
Common-Sector (¯σ∆) 0.0061 0.8146 0.0217 0.8284
B. 2000–2007
Actual (¯σΩ) 0.0071 1.0000 0.0233 1.0000
Firm-specific (¯σF ) 0.0030 0.4279 0.0073 0.3133
Common-Sector (¯σ∆) 0.0054 0.7637 0.0181 0.7785
C. 2008–2014
Actual (¯σΩ) 0.0081 1.0000 0.0296 1.0000
Firm-specific (¯σF ) 0.0031 0.3883 0.0084 0.2863
Common-Sector (¯σ∆) 0.0069 0.8728 0.0257 0.8855
86. Extensions and Robustness
2. Gross Output (GO) Based Shocks:
qit = αl lit + αk kit + αmmit + ˜ωit
˜git = ˜ωit − ˜ωi,t−1
When estimating yit = βl lit + βk kit + ωit (where yit = qit − mit ) we impose
αm = 1 (1:1 relationship b/w Q and M).
Direct implication: ωit larger, by construction, than ˜ωit .
Conceptually taken into account by aggregating with Domar weights, but there
still is the potential that GO based idiosyncratic shocks are not found to have a
significant impact on aggregate fluctuations.
Control for this issue by adopting a GO based specification, and proceeding with
Domar aggregation
˜gΩt|τ
=
i
Qi,τ−1
Yτ−1
˜git =
s
Qs,τ−1
Yτ−1
˜δst +
i
Qi,τ−1
Yτ−1
˜eit
87. Extensions and Robustness
2. Gross Output Based Shocks: Relative Standard Deviations
Whole Economy Manufacturing
St.Dev. Relative SD St.Dev. Relative SD
A. 2000–2014
Actual (¯σΩ) 0.0080 1.0000 0.0279 1.0000
Firm-specific (¯σF ) 0.0021 0.2624 0.0068 0.2460
Common-Sector (¯σ∆) 0.0075 0.9413 0.0260 0.9304
B. 2000–2007
Actual (¯σΩ) 0.0072 1.0000 0.0237 1.0000
Firm-specific (¯σF ) 0.0019 0.2650 0.0059 0.2505
Common-Sector (¯σ∆) 0.0066 0.9138 0.0213 0.8955
C. 2008–2014
Actual (¯σΩ) 0.0089 1.0000 0.0327 1.0000
Firm-specific (¯σF ) 0.0023 0.2593 0.0078 0.2408
Common-Sector (¯σ∆) 0.0086 0.9727 0.0315 0.9703
88. Extensions and Robustness
3. Control for heterogeneous responses to common shocks:
in the baseline specification, firms are not allowed to react to common shocks in
different ways.
Therefore, we might incorrectly interpret as idiosyncratic shocks what are,
instead, heterogeneous responses to common shocks.
To control for this: isolate idiosyncratic shocks from the following
git = δjt +
K
k=1
δjt × zkit + β Zit + eit
where firm-level characteristics Zit = (z1it , ..., zkit , ..., zKit ) include
(i) Size (number of employees quartile dummies);
(ii) Age (dummy for whether the firm is more or less than 5 years old)
(iii) Markups (estimated at firm-level as in De Loecker and Warzynski, 2012)
89. Extensions and Robustness
3. Control for heterogeneous responses to common shocks: Relative Standard Deviations
I. Value Added Based Specification
Differing Sensitivity By:
Benchmark (i) Size (ii) Age (iii) Markup (iv) All
A. 2000–2014
0.4181 0.4107 0.4120 0.4107 0.3990
B. 2000–2007
0.4375 0.4206 0.4218 0.4247 0.3950
C. 2008–2014
0.3959 0.3994 0.4008 0.3948 0.4036
90. Extensions and Robustness
3. Control for heterogeneous responses to common shocks: Relative Standard Deviations
II. Gross Output Based Specification
Differing Sensitivity by:
Benchmark (i) Size (ii) Age (iii) Markup∗ (iv) Markup∗∗ (v) All
A. 2000–2014
0.2621 0.2650 0.2664 0.2773 0.3133 0.2694
B. 2000–2007
0.2650 0.2648 0.2669 0.2824 0.3236 0.2785
C. 2008–2014
0.2588 0.2651 0.2657 0.2713 0.3016 0.2590
∗
Labor-based markups
∗∗
Materials-based markups
91. Outline
Introduction
Conceptual Framework
Empirical Implementation
Granular Residual (Gabaix, 2011)
Contributions to Aggregate TFP Volatility (di Giovanni et al.,
2014)
Data and Preliminary Statistics
Results
Granular Residual
Relative Standard Deviations
Channels for Firms’ Contributions
Direct Effect’s Contribution
Firm Linkages’ Contribution
Extensions and Robustness
Summing Up
93. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
94. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
The impact of idiosyncratic productivity shocks on Aggregate TFP volatility is
found to be around 30% across different specifications;
95. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
The impact of idiosyncratic productivity shocks on Aggregate TFP volatility is
found to be around 30% across different specifications;
We exploit the decomposition proposed by Carvalho and Gabaix (2013) and
di Giovanni et al. (2014), and find that:
96. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
The impact of idiosyncratic productivity shocks on Aggregate TFP volatility is
found to be around 30% across different specifications;
We exploit the decomposition proposed by Carvalho and Gabaix (2013) and
di Giovanni et al. (2014), and find that:
the contribution of the linkages component to firm-specific aggregate
volatility is more relevant than that of the direct effect (∼ 80% vs
∼ 60%), especially when focusing on manufacturing (∼ 90% vs ∼ 40%);
97. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
The impact of idiosyncratic productivity shocks on Aggregate TFP volatility is
found to be around 30% across different specifications;
We exploit the decomposition proposed by Carvalho and Gabaix (2013) and
di Giovanni et al. (2014), and find that:
the contribution of the linkages component to firm-specific aggregate
volatility is more relevant than that of the direct effect (∼ 80% vs
∼ 60%), especially when focusing on manufacturing (∼ 90% vs ∼ 40%);
The contribution of the direct effect —though remaining well below that
of the linkages channel— slightly grows in importance during the crisis;
98. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
The impact of idiosyncratic productivity shocks on Aggregate TFP volatility is
found to be around 30% across different specifications;
We exploit the decomposition proposed by Carvalho and Gabaix (2013) and
di Giovanni et al. (2014), and find that:
the contribution of the linkages component to firm-specific aggregate
volatility is more relevant than that of the direct effect (∼ 80% vs
∼ 60%), especially when focusing on manufacturing (∼ 90% vs ∼ 40%);
The contribution of the direct effect —though remaining well below that
of the linkages channel— slightly grows in importance during the crisis;
The direct and linkages components are not mere aggregate by-products
of measurement error of TFP at the micro level: a counterfactual direct
component would have an impact 3 times smaller; more concentrated
sectors show higher direct volatilities as well; more interconnected couples
of sectors show higher linkages volatilities.
99. Summing Up
Using data from CERVED and INPS, we investigate the granular sources of the
Italian business cycle, i.e. the question of whether firm-level dynamics have an
impact on aggregate fluctuations;
The impact of idiosyncratic productivity shocks on Aggregate TFP volatility is
found to be around 30% across different specifications;
We exploit the decomposition proposed by Carvalho and Gabaix (2013) and
di Giovanni et al. (2014), and find that:
the contribution of the linkages component to firm-specific aggregate
volatility is more relevant than that of the direct effect (∼ 80% vs
∼ 60%), especially when focusing on manufacturing (∼ 90% vs ∼ 40%);
The contribution of the direct effect —though remaining well below that
of the linkages channel— slightly grows in importance during the crisis;
The direct and linkages components are not mere aggregate by-products
of measurement error of TFP at the micro level: a counterfactual direct
component would have an impact 3 times smaller; more concentrated
sectors show higher direct volatilities as well; more interconnected couples
of sectors show higher linkages volatilities.
Taken together, the results suggest that even in an economy such as the Italian
one —dominated by many small firms— firm-level idiosyncratic dynamics do
have an impact on the aggregate fluctuations.
100. Selected References
Acemoglu, D., V. M. Carvalho, A. Ozdaglar, and A. Tahbaz-Salehi (2012):
“The network origins of aggregate fluctuations,” Econometrica, 80(5), 1977–2016.
Ackerberg, D. A., K. Caves, and G. Frazer (2015): “Identification properties of
recent production function estimators,” Econometrica, 83(6), 2411–2451.
Carvalho, V. and X. Gabaix (2013): “The great diversification and its undoing,”
The American Economic Review, 103(5), 1697–1727.
De Loecker, J. and F. Warzynski (2012): “Markups and firm-level export
status,” The American Economic Review, 102(6), 2437–2471.
di Giovanni, J., A. A. Levchenko, and I. M´ejean (2014): “Firms, destinations,
and aggregate fluctuations,” Econometrica, 82(4), 1303–1340.
Gabaix, X. (2011): “The granular origins of aggregate fluctuations,” Econometrica,
79(3), 733–772.
Hulten, C. R. (1978): “Growth accounting with intermediate inputs,” The Review
of Economic Studies, 45(3), 511–518.
Lucas, R. E. (1977): “Understanding Business Cycles,” Carnegie-Rochester
Conference Series on Public Policy, 5, 7–29.