Abstract
Abstract
The purpose of the study 3
This article is a part of a PhD thesis submitted at School of Accounting, Dongbei University of Finance and Economics, Dalian, P. R. China.
Introduction
There are two competing theories of capital structure: trade-off theory (TOT) and pecking order theory (POT). Most of the research studies in the field of capital structure use these theories to explain determinants of capital structure. The trade-off theory was given by Modigliani and Miller, (1963). They argue that there exists a trade-off between costs and benefits associated with leverage and define breakeven point of these leverage-related costs and benefits as optimal (target) capital structure. On the other hand, pecking order theory states a specific order of financing where internal funds are considered as first choice; external debt second choice; and equity as a last choice (Donaldson, 1961; Myers & Majluf, 1984). Accordingly, pecking order theory states that the firms follow a specific order of financing while trade-off theory explains that the firms follow a target capital structure.
The empirical studies carried out internationally as well as in Pakistan provide evidence both in favor of pecking order theory and trade-off theory (Ahsan, Wang, & Qureshi, 2016a; Booth, Aivazian, Kunt, & Maksimovic, 2001; Sheikh & Qureshi, 2014; Titman & Wessels, 1988). All of these studies have applied time series or panel data regression analysis to find out determinants of capital structure and to decide between pecking order and trade-off theory. The purpose of this study is to decide between pecking order and trade-off theory while using a different approach. We use mean reversion property of target (optimal) capital structure to find out the existence of target (optimal) capital structure during different life cycle stages of the firms operating in Pakistan. Further, we follow a multivariate approach to classify firms into different life cycle stages and apply panel data unit root test to a large dataset of Pakistani listed non-financial firms to check if their capital structure is mean-reverting along their life cycle or not.
The study classifies firms into growth, maturity and decline stage and contributes to the literature by discovering that growing as well as mature firms do follow target capital structure but declining firms do not have target capital structure.
Apart from the Introduction section, the rest of the paper is organized in the following manner: next section describes theoretical framework, data and methodology; the empirical results and their discussion is presented in another section; and last section is about the conclusions drawn and suggested directions for future research. References have been provided at the end.
Theoretical Framework, Data, and Methodology
A firm progresses through different stages during its life cycle. These life cycle stages starts from birth and ends at death. However, theorists explain various number of life cycle stages of a firm. Such as, some theorist explain that structure and strategies of firms vary in growth, maturity, and decline stage (Anthony & Ramesh, 1992; Chandler, 1962). Some others explain four life cycle stages including birth, growth, maturity, and revival (Miller & Friesen, 1980), and some explains birth, growth, maturity, revival, and decline (Dickinson, 2011). But most of these theorists agreed upon growth, maturity, and decline stages. Accordingly, in this study we also classify firm-year observations into growth, maturity and decline stages.
Further, empirical studies use the mean leverage ratio as a proxy of target leverage (Frank & Goyal, 2009; Jõeveer, 2013) for firms and attribute of stationarity of the data necessitates reversion towards its mean value. This attribute can be used to find out the existence of target leverage, and consequently to decide between trade-off theory and pecking order theory of capital structure (Ahsan, Wang, & Qureshi, 2016b). Furthermore, unit root analysis can be used to find out the stationarity of the data (Bontempi, 2002).
To examine mean reversion of capital structure in Pakistan, we develop a unique dataset of all Pakistani non-financial firms listed at PSE (Pakistan Stock Exchange) taken from the State Bank of Pakistan (SBP) publications for the period 1972–2010 (SBP 1972–2010). The time (years) and space (firms) dimensions make it an unbalanced panel dataset comprising 13 sectors and 13,375 firm-year observations.
Life Cycle Variables and Classification Method
Due to the use of five years’ prior data to calculate median values for the dividend payout ratio and sales growth, our total number of firm-year observations is reduced from 13,375 to 8,419. The summary in Table 2 indicates that we have 1,713 firm-year observations for growth stage, 6,255 firm-year observations for the mature stage, and 451 firm-year observations for the decline stage.
Sector and Life Cycle Stage-wise Number of Firms-year Observations
The growing use of panel data in empirical studies has forced econometrics to extend time series unit root tests to panel data. Consequently, there are a number of unit root tests available for panel data such as: LLC (Levin, Lin, & Chu, 2002), IPS (Im, Pesaran, & Shin, 2003), and Fisher type (Choi, 2001; Maddala & Wu 1999;) tests. These panel data unit root tests are different from each other in their technique and assumptions. We compare these tests and finally choose Fisher test for our study due to following reasons;
LLC requires independence of each cross section and is not applicable if there is cross-sectional correlation. LLC is also restrictive to the assumption that all cross sections have or do not have a unit root while IPS and Fisher type tests relax this restrictive assumption and allow some of the groups to be non-stationary while others may not, under the alternative hypothesis (Baltagi, 2005; Maddala & Wu, 1999). Both, Fisher test and IPS test relax the restrictive assumption of LLC that is why they are comparable. The Fisher test is non-parametric while the IPS test is parametric. Being a parametric test IPS requires t-bar distribution, which is based on mean and variance of t-statistics. IPS computes t-distribution tables for different values, sample sizes, and number of lags based on ADF test statistics. The validity of these tables is conditional to the ADF test being used for unit root tests. Moreover, the IPS prepared tables also faces problems while dealing with different lengths of time series for different samples. While Fisher test, being non-parametric, do not have such limitations. It can be used with ADF test as well as with any other unit root test and lag lengths can also be determined separately for each sample. Furthermore, the Fisher test also allows T (time dimension) to be different for each i. It follows that the Fisher test does not require a balanced panel (Choi, 2001) and considered as a preferred choice for our study because, we are using unbalanced panel of 13,375 firm-year observations. In the following equation, we present our panel data unit root (Fisher test) model:
This model contains the following hypothesis:
Leverage is our variable of interest in this study. Different methods can be used to measure leverage. We measure leverage using three proxies: short-term leverage as the ratio of short-term liabilities to total assets; long-term leverage as the ratio of long-term liabilities to total assets; and total leverage as the ratio of total liabilities to total assets.
Empirical Results and Their Discussion
In this section, we present and discuss descriptive statistics of life cycle as well as leverage ratios and empirical results of unit root analysis for three different measurements of leverage ratios during growth, maturity, and decline stages.
Descriptive Statistics
Descriptive Statistics for Life Cycle Variables Used to Classify Firms
Descriptive Statistics for Leverage Ratios during Different Life Cycle Stages
Empirical Analysis
Panel Data Unit Root Results during Growth Stage
In Table 6, we present the results of unit root analysis for short-term, long-term, and total leverage ratios during the mature stage. For the mature stage, we have 551 firms and 6,255 firm-year observations available for the analysis. The results of unit root analysis finds no unit root in the short-term, long-term, as well as total leverage ratios during the mature stage also and rejects the null hypothesis. It explains mean reverting short-term, long-term, as well as total leverage ratios and depicts trade-off financing behavior of Pakistani listed non-financial firms during their mature stage.
Panel Data Unit Root Results during Mature Stage
Panel Data Unit Root Results during Decline Stage
Conclusions
We apply panel unit root test developed by Fisher on a unique and large dataset comprising of 13,375 firm-year observations of Pakistani non-financial firms listed on Pakistan Stock Exchange spread over 39 years period (1972–2010) to provide some evidence on their leverage behavior. If the leverage ratios do not have unit root they are stationary and mean-reverting, then the firms are expected to have target leverage ratios as explained by trade-off model. Otherwise, they are non-stationary and not mean-reverting, and as such the firms may not have target leverage ratios and may not depict trade-off leverage behavior. Further, we follow multivariate approach to classify firms into growth, maturity and decline stages.
The results of the study suggest that short-term leverage is a main source of financing of Pakistani listed non-financial firms throughout their life cycle. Further, the results explains that during growth and maturity stage Pakistani non-financial listed firms do have a target capital structure in line with TOT but declining firms do not have any target leverage ratio and they may follow pecking order theory. If this is the case, growing and mature Pakistani firms definitely strive to achieve their target leverage ratios. Further research can be carried out to find out the speed of adjustment of these firms towards their target leverage ratios.
Footnotes
