1. Introduction
Historically, Gibrat (1931) [
1] was the first scholar to propose a stochastic process in order to model the growth of firms based exclusively on general probabilistic concepts. His basic hypothesis states that the logarithmic growth rate of a firm’s size is independent of its level and it is normally distributed. The normal distribution assumption can be justified on the premise of the Central Limit Theorem (CLT hereafter). The logarithmic growth rate of a firm in a given time period (one year, for instance) can be decomposed as a sum of a large number of shocks hitting the firm at a higher frequency (e.g., daily). Within this time decomposition, the emergence of the normal distribution of growth rates is a natural consequence of the CLT, assuming that the shocks are independent and identically distributed. Under these assumptions, the distribution of firms’ size is lognormal. From an economic perspective, Gibrat’s hypotheses are compatible with an ensemble of
independent firms, experiencing, possibly, a common trend and idiosyncratic destinies. Gibrat’s statistical approach has been generalised in order to account for other economic phenomena, such as the entry and exit of firms in a market and the turbulence and the learning of firms, leading Sutton to call for the existence of Gibrat’s legacy [
2].
Challenging Gibrat’s hypothesis of normality, many authors (see [
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14]) have empirically shown that firms’ growth rates follow a Laplace distribution rather than a normal distribution. Starting from the basic assumption of iid shocks leading to a Gaussian distribution, the empirical identification of the Laplace distribution can be alternatively interpreted as the imprint of a systemic dependence among the shocks hitting all firms. In order to account for the “Laplacian” deviations from the Gaussian hypothesis, one must replace the assumption of iid shocks by perturbations characterised by some degree of system-wide correlation due to systemic economic interactions among firms. The Laplace distribution of cross-sectional firms’ growth rates, thus, can be thought of as the macroscopic evidence of the existence of complex interactions among firms. Some models have been proposed in order to account for the emergence of the Laplace distribution. Bottazzi and Secchi (2006) [
6] show that the Laplace distribution stems from a competitive context in which firms are able to seize new growth opportunities proportional to opportunities already taken. Under the resource-based view of the firm [
15], Coad and Planck (2012) [
16] consider a mechanism of employment growth in a hierarchy, leading to an exponential distribution of firm size and a Laplace distribution of growth rates.
Recently, some authors (see [
17,
18,
19]) proposed a new focus to analyse firm dynamics from Gibrat’s perspective beyond the growth rates of firm size. They claim that a more informative quantity to account for the dynamics of the ensemble of firms in a competitive environment is to consider profit rates instead of growth rates as the key measure of firm performance. This change of focus allows relying on the general principle of the tendency for equalisation of profit rates based on the idea of classical competition. In this respect, Alfarano and Milakovic (2008) [
8] introduced a theoretical framework for the profit rate distribution by considering as the intellectual base Adam Smith’s notion of classical competition [
20], which describes a negative feedback mechanism: capital seeks out those sectors in which profit rates are higher than the economy-wide average, essentially attracting labour, raising output, reducing prices and eventually profit rates. Capital, thus, leaves the sector giving rise to an increase in prices and profit rates for those firms that remain in the industry. The entire process tends to equalise profit rates across sectors and firms. The idea of classical competition can be framed in terms of a statistical equilibrium model for the profit rate distribution, which leads to an Exponential Power or Subbotin distribution [
21]. Such theoretical framework has been empirically tested in several contributions [
17,
18,
22], showing that the profit rate distribution can be described by a Laplace distribution, whose first and second moments are very stable over time, much more than the corresponding moments of the growth rate distribution. Interestingly, it has been shown that such stability emerges when one restricts the analysis to firms that survived for a sufficiently long time (more than 25 years) [
17]. The entry and exit dynamics of firms are, therefore, excluded by construction from the analysis. In this regard, Mundt and Oh (2019) [
23] show that the Laplace distribution is not flexible enough to describe the profit rate distribution when entry and exit dynamics of firms are included. They observe an empirical profit rate distribution that exhibits a higher degree of leptokurtosis and a significant asymmetry when compared to a symmetric Laplace distribution. Hence, Mundt and Oh (2019) [
23] generalise the model proposed by Alfarano et al. (2012) [
17] in order to include changes in the nature of the competitive environment and the strength of competitive pressure between entering/existing and incumbent firms. Their model shows that these features can be accounted by the AEP distribution, proposed by Bottazzi and Secchi (2011) [
9]. The AEP generalises the Subottin distribution in order to include a given degree of asymmetry.
To shed more light on this strand of literature, we study a large dataset of 35.910 Spanish long-lived firms, analysing the recent financial crisis and its business cycle phases: the period of the real estate bubble (1998–2007), the subsequent crisis (2008–2013) and the period of economic recovery (2014–2016). The large dataset at our disposal allows for an extensive analysis of the Laplacian hypothesis of profit rate distribution and its stability over time. The contribution of our paper is threefold. First, following Alfarano et al. (2012) [
17] and Mundt and Oh (2019) [
23], we examine whether the empirical profit and growth rate distributions of Spanish firms are described by the Laplace, Subbotin or AEP distribution. Compared to Mundt and Oh (2019) [
23], our analysis is not limited to profit rates but also includes the comparison to growth rates. Second, we analyse how the empirical distribution changes according to the different firm sizes and the phases of the business cycle. Finally, our analysis allows us to understand whether the astonishing stability of the profit rate cross-sectional distribution is an intrinsic characteristic of surviving firms or other conditionalities should be considered. Understanding the cross-sectional distribution of growth and profit rates during the different phases of the business cycle can help us to shed more light on macroeconomic fluctuations [
24,
25,
26,
27]. Indeed, Haltiwanger (1997) [
28] stated that “it is becoming increasingly apparent that changes in the key macroaggregates at cyclical and secular frequencies are best understood by tracking the evolution of the cross-sectional distribution of activity and changes at the micro level.” The availability of micro-data has allowed scholars to study how the microeconomic adjustment behaviour of firms affects the aggregate dynamics of the economy. For example, Higson et al. (2002) [
24] show that fastest growers and declining firms seem to be indifferent to recessions, in the same line as Geroski and Gregg (1997) [
29]. De Veirman and Levin (2011) [
30] analyse trends and cycles in the volatility of U.S. companies observing that firm-specific volatility is not an important driver of the business cycle. Holly et al. (2013) [
31] underline that changes in the density of firm growth are a relevant factor to analyse the evolution of the business cycle. Bachmann and Bayer (2014) [
32] propose a heterogeneous-firm business cycle model that is able to replicate the procyclical behaviour of the empirical cross-sectional dispersion of firm-level investment rates.
The paper is structured as follows. After providing a summary in the introduction, we give a description of our data in
Section 2. The employed methodology for the empirical analysis is described in
Section 3. The results of the empirical analysis are shown in
Section 4, distinguishing between symmetric and asymmetric distributions. Finally,
Section 5 summarises the main findings of the paper.
2. Data
The dataset is sourced from the System of Analysis of Iberian Balance Sheets and it offers information over the balance sheet of 2,000,000 Spanish firms from 1985 to 2016. Thus, we can examine the evolution of the distribution of growth and profit rates during different phases of the business cycle. As stated in the introduction, our empirical analysis focuses on long-lived firms. We filter a total of 35,910 firms that have been present in the market for the whole period. All firms from the financial sector (Standard Industrial Classification (SIC) codes 6000–6799) have been excluded since their total assets are on average about one order of magnitude larger than firms included in all the other sectors. This is due to the different nature of the banking/financial sector, where total assets can be increased due to the financial intermediation activity. Our dataset allows generalising the previous findings on the distributional properties of the profit rates, since we extend the number of firms in more than two orders of magnitude, from a few hundred to several thousand, whose sizes span five orders of magnitude. In order to compare our results to the previous literature, we consider four groups of firms according to their sales in 2016. These groups include the 200, 1,000, 10,000 largest firms and the entire sample.
As a starting point, we consider the 200 largest firms due to two main reasons. First, we take as intellectual base Gabaix’s granular hypothesis [
26]. His seminal paper rests on the idea that the idiosyncratic shocks to the largest firms account for a significant fraction of the GDP fluctuations. Following Gabaix (2011) [
26], one-third of aggregate fluctuations in US GDP growth can be explained by the idiosyncratic shocks of the 100 largest firms. Blanco-Arroyo et al. (2018) [
33] and Blanco-Arroyo et al. (2019) [
34] show that the Spanish economy is also characterised by granular fluctuations since the granular residual of the 100 largest firms accounts approximately for 45% of GDP variations. The second reason is related to the fact that we employ the AEP distribution to characterise the profit and growth rate distribution. By means of numerical simulations, Bottazzi and Secchi (2011) [
9] state that “the bias of the maximum likelihood estimators, being very small, can be safely ignored at least for samples with more than 100 observations”. Therefore, we start the empirical analysis considering the largest 200 firms to ensure the reliability of the estimated parameters.
As the first step, we compute the logarithmic growth rate for each firm
i defined as:
where
t denotes the year and
the firm size, whose proxy is the value of total assets or sales [
11,
35].
The variable chosen as a proxy for profit rate is the return on assets (
ROA), which is defined as earnings before interest and taxes (
EBIT) divided by total assets (
TA) of firm
i at time
t,
A visual inspection to
Figure 1a,b shows that the median of profit rates for the largest 200 long-lived firms exhibit considerable stability over time compared to the median growth rates of total assets and sales, which instead exhibits a much higher volatility. The time evolution of the median of profit and growth rates is also reported by Alfarano et al. (2012) [
17] using a sample of publicly traded US companies, observing similar results. Our results are also in line with Mundt et al. (2014) [
36], who find that the median of profit rates is much more stable than the median of growth rates in more than 40 countries using a dataset of publicly traded companies. Moreover, we confirm the results reported by Coad et al. (2013) [
37], who observe much higher stability of the profit rate cross-sectional average when companies survive more than 11 years. We observe that the median of profit rates exhibits higher stability compared to the median of growth rates even when considering the entire sample of long-lived firms. However, it shows higher fluctuations with respect to the sample composed by the 200 largest firms, due to the impact of the smaller firms. In both cases reported in
Figure 1, the first two moments of the profit rate distribution are more stable than those of growth rates.
Under a Gaussian hypothesis for the distribution of profit and growth rates, the analysis of the first two moments would be a sufficient statistic. However, an extensive literature in industrial dynamics (see e.g., [
2]) shows that the empirical distribution of relevant measures of firm performance exhibits significant deviations from the normality assumption. We, therefore, have to characterise the entire distribution of profit and growth rates. Following the literature [
6], we consider the normalised logarithmic size:
where
N is the number of considered firms in the sample, namely 200, 1000, 10,000 and the entire sample. We define the annual growth rate of a firm
i as:
where
t denotes time and
denotes normalised logarithm of firm size. Profit rates are not manipulated and simply remain in their raw form.
3. Methodology
Alfarano and Milakovic (2008) [
8] introduce a theoretical framework to analyse the distribution of profit rates by considering as an intellectual base Adam Smith’s notion of classical competition [
20]. It describes a negative feedback mechanism in the reallocation of capital in the perpetual search for profitability, leading to a tendency for the equalisation of profit rates among competitive economic activities. In the empirical data, however, the complete elimination of profit rates differentials is never achieved. Alfarano et al. (2012) [
17], thus, express the outcome of classical competition in terms of a statistical equilibrium model, considering that the complexity of the competitive interactions among firms leads to a non-degenerate distribution of profit rates. In particular, firms disperse their profit rates, denoted as
x, around a measure of central tendency, denoted as
m, which represents the economy-wide profit rate. The tendency for equalisation of profit rates can be encoded as a moment constrain on the dispersion of their distribution measured by the standardised
-th moment:
In order to obtain the profit rate distribution, Alfarano and Milakovic (2008) [
8] employ the Maximum Entropy Principle (MEP), which establishes a unique connection between a set of given moment constraints and a probability distribution. The MEP yields the combinatorially most likely distribution maximising the multiplicity of feasible assignments given the moment constrains (see [
38]). The result of MEP for the moment constraint in Equation (
5) is an Exponential Power or Subbotin distribution, defined as
This symmetric distribution is characterised by three parameters: a location parameter
m, a scale parameter
and a shape parameter
. Depending on the value of the shape parameter, we have three different cases: (i) a platykurtic distribution for
, (ii) a leptokurtic distribution for
, and (iii) a Gaussian distribution for the edge case
. In particular, the Subbotin distribution reduces to the Laplace distribution when
. The distribution in Equation (
6) has been widely employed in the literature of industrial dynamics [
5,
6,
16,
17,
18,
22] to characterise the empirical distribution of profit and growth rates of firm size, essentially because it interpolates between the Gaussian and the Laplace distribution. Following the growth rate literature [
6,
16,
35], we consider the Laplace distribution as the benchmark to compare the estimated results.
In this paper, we complement the distributional analysis based on the symmetric distribution of Equation (
6) by using the AEP distribution. Mundt and Oh (2019) [
23], generalising the result given by Alfarano and Milakovic (2008) [
8], provide an economic foundation for the AEP distribution within a statistical equilibrium approach that includes structural differences between the right and left part of the distribution. In particular, they show that the former reflects the activity of incumbent firms while the latter represents the activity of entering/existing companies characterised by low/negative profit rates. Instead of a symmetric behaviour around the measure of central tendency, defined by the Equation (
5), which implies the emergence of a symmetric distribution, they define two different conditional measures of dispersion around
m:
for
and
for
, where
l and
r refer to the left and right part of the distribution, respectively. Using the MEP, the probability distribution for the variable
x based on the two moment constraints is the following:
where
,
is the Heaviside function (the function
is equal to 1 for
, and 0 for
) and
is the normalisation constant with
the Gamma function. Equation (
7) is a five-parameter family of distributions that is characterised by the location parameter,
m, which is the mode of the distribution, two shape parameters,
and
, describing the density in the lower and upper tail respectively, and two scale parameters,
and
, connected with the distribution width below and above
m. The Laplace distribution is nested in the AEP when
and
. Note that the parameter
m in the Laplace distribution represents the mean, the median and the mode of the distribution. Those three measures of central tendency, however, might not coincide in the AEP distribution. In this case,
m represents the mode of the AEP distribution.
5. Conclusions
In this paper, we shed some light on the firm dynamics literature by analysing to what extent the Laplace distribution describes the Spanish long-lived firms’ distribution of profit and growth rate, against its alternative more general distributions, namely Subbotin and AEP. Moreover, compared to recent literature, we analyse the effect of the different phases of the business cycle and the firm size on the distributional characteristics of profit and growth rates.
We find evidence of systematic deviations of the profit rate distribution from the Laplace benchmark when small firms are included in the analysis. The empirical distribution becomes more leptokurtic without changing the scale parameters. Therefore, the Laplace benchmark turns out to be a reasonable approximation if we limit the sample to large and surviving firms. Relaxing the symmetric constraint, the use of the AEP distribution shows that, instead of a Laplace, the better approximation for firm profit rate distribution is an asymmetric Laplace. Interestingly, except for the location parameter, the shape and scale parameters do not depend on the business cycle phase. Small firms, instead, show a much higher dependence of their profit rates on the business cycle phase, signalling a marked difference with large firms. Taking into account these results, we underline the robustness of the large firms during the financial crisis in terms of profitability given (i) the significant larger dispersion of the right part of the distribution, compared to the left one, and (ii) the absence of relation between the time series of GDP growth rates and the time series of the estimates of , , and for the largest 200 long-lived firms’ profit rates. However, this robustness is lost when including small firms in the sample since (i) we observe that the dispersion of the left part of the distribution is significantly larger than the right one during the years of the downturn, and (ii) the estimates of the entire sample show a remarkable relationship with the GDP growth rates.
On the other hand, focusing on growth rates, we observe a similar tendency compared to profit rates given the effect of the crisis on small firms’ growth distribution (). This result is supported by the stronger correlation between the time series of the estimate parameters and GDP growth rates when including small firms in the sample. Interestingly, we observe that profit and growth rates of total assets show similar dynamics in terms of dispersion, while growth rates of total assets and sales are more similar regarding the shape of the distribution.
Given the results reported in this paper, we infer that the largest firms are more robust to downturns compared to the small firms, due to their invariant distributional characteristics during crisis periods. Consequently, this study provides some insights to policymakers on how turmoil affects firms depending on their size. In particular, the role that the largest firms have on the business cycle is now better understood [
26]. Moreover, given that the present analysis is based on a sample of long-lived firms of different sizes, the distributional analysis allows a precise evaluation of the risk related to large downturns in firm profitability conditional on firm size. This information is extremely useful for those investors interested in investing in real economic activity.
Future research could be focused on three directions. First, considering different countries in order to analyse their distributional properties according to their phase in the business cycle. Second, analysing the causal dependencies between the variables of the AEP distribution and GDP growth rates, when longer data sets are available. Finally, we have identified that size is an important factor in the distributional properties of profit and growth rates. However, other firms’ characteristics can be relevant in the dynamics of the distribution (see Mundt et al. (2020) [
42]). Thus, in future research, we plan to study the impact of other firm characteristics on the dynamics of the distribution of profit and growth rates.