Abstract
In the literature, it is highlighted that the deterministic nature of the data envelopment analysis–based productivity measures makes them sensitive to sample characteristics. However, the majority of the related empirical studies ignore the potential bias in their data envelopment analysis–based productivity estimations. This article illustrates how the order-α quantile-type estimators can be applied to construct a robust version of the Malmquist productivity indices. Using the order-α estimators, we construct a Malmquist productivity index alongside with two well-known decompositions. The proposed productivity indicator is less sensitive to potential outliers and extreme values. Then, as an illustrative example, we apply the quantile-type productivity index on a sample of 270 hotels operating in the Balearic Islands over the period 2004-2013. The productivity levels alongside with their components are analyzed during the global financial crisis period.
Keywords
Introduction
The service sector is an important element of countries’ economic growth strategy. As a result, there is a necessity for policymakers to be able to measure, monitor, and analyze service productivity (Lundberg, 1990). Especially, the measurement of hotels’ productivity is an open research challenge for scholars using different methodological tools, different sample sizes, different variables, and different assumptions regarding the estimated production function (Assaf & Josiassen, 2016; Assaf & Matawie, 2009; Assaf & Tsionas, 2018a, 2018b; Barros, 2005a, 2005b; Barros & Santos, 2006). Two main methodological approaches can be adopted to measure hotel productivity. The first one is the parametric approach, known also as the stochastic frontier approach, under which the estimation is based on the advances of econometric techniques. The second approach is known as the data envelopment analysis (DEA) and is based on the advances of mathematical programming. Both approaches exhibit several advantages and disadvantages, and their use is determined most of the time from the problem at hand. The focus of this article is based on the estimation of productivity through the DEA framework. Chatzimichael and Liasidou (2019) pointed out that the DEA-based productivity measures are more popular among the scientists measuring hotels’ productivity levels since they provide greater flexibility in terms of the assumptions imposed in relation to the estimated production function.
Based on the relative literature, Färe and coworkers’ (Färe et al., 1992, Färe, Grosskopf, Lindgren, & Roos, 1994; Färe, Grosskopf, Norris, & Zhang, 1994) Malmquist productivity decomposition is the most popular productivity measure. An essential part of the Malmquist productivity index (MPI) is the estimation of distance functions (DFs). The DEA approach for estimating DFs is very popular among scholars when measuring hotels’ efficiency and productivity levels (Brown & Ragsdale, 2002; Cordero & Tzeremes, 2017; Dolasinski et al., 2019; Goncalves, 2013; Walheer & Zhang, 2018). The studies by Hwang and Chang (2003) and Barros and Alves (2004) were the first to apply the DEA-based MPI in order to measure and decompose the productivity of different hotel sectors. Similarly, Assaf and Barros (2011) applied Färe and Grosskopf’s (1996) productivity decomposition to evaluate hotels’ productivity in the Gulf region. However, the flexibility provided by the DEA-based framework comes with several weaknesses.
As has been suggested by Assaf and Tsionas (2018a, 2018b), DEA-based productivity measures are subject to potential bias since the determinist nature of DEA estimators can be influenced from sample characteristics. Tzeremes (2019) asserted that different outliers, extreme and atypical values included in a data sample, can distort the estimated productivity levels providing the analyst with a pseudo productivity view. Even though such a limitation is well documented in the relative literature, empirical studies measuring hotel productivity avoid tackling such a potential source of bias (Assaf & Josiassen, 2016).
To minimize the potential measurement bias, Assaf and Agbola (2011) applied a bootstrapped-based MPI on a sample of 34 Australian hotels over the period 2004-2007. They applied Simar and Wilson’s (1999) bootstrap procedure to provide a statistical significance of their measurement. More recently, Kularatne et al. (2019) applied Simar and Wilson’s (2007) double bootstrap algorithm on a sample of 24 hotels operating in Sri Lanka over the period 2010-2014. Kularatne et al. (2019) applied the double bootstrap approach to obtain bias-corrected efficiency estimates. Furthermore, as in the case of Assaf and Agbola (2011), Kularatne et al. (2019) further applied a bootstrapped MPI, which was based on Simar and Wilson’s (1999) bootstrap procedure. By doing so, they created confidence intervals for the estimated productivity measures and their components. In both Assaf and Agbola (2011) and Kularatne et al. (2019), the measurement and the decomposition of the MPI was based on Färe, Grosskopf, Lindgren, and Roos (1994) assuming constant returns to scale (CRS).
Serra and Lansink (2014) argued that the main assumption of the estimates derived from the DEA frontier lies in the fact that all units belong to the attainable production set. Therefore, superefficient units act as outliers having a direct impact on the estimated efficiency scores. As a result, the DEA-based DFs used to construct and decompose the DEA-based MPIs will suffer from the same potential bias estimation that is attributed to specific sample characteristics. According to Serra and Lansink (2014), this potential problem can be resolved by applying robust (partial) frontiers that avoid enveloping all data points that are included in the evaluated sample. According to Daraio and Simar (2005, 2007), there are two well-known robust estimators. These are the order-m (Cazals et al., 2002) and the order-
This article contributes to the relative literature by creating an order-
Our article utilizes these estimators to construct order-
Methodological Framework
Let
In expression (1),
We can calculate
Daouia and Simar (2007) argued that the order-
The production function expressed in (4) represents the level of output not exceeded by
When
To construct the order-
Following Shephard (1970), the output DF can be expressed as
Given that
Specifically, equation (8) represents an Order-
In the expression (9),
In contrast to the two previous decompositions, we utilized an order-
The last step of our analysis was the estimation strategy of the order-
Empirical Findings and Discussion
Following the relative literature of hotels’ efficiency and productivity measurements (Assaf & Agbola, 2014; Assaf & Barros, 2011; Assaf et al., 2011; Assaf & Josiassen, 2016; Cordero & Tzeremes, 2017; Tzeremes, 2019), we defined hotels’ production function having as inputs total employees and total fixed assets (measured in millions of euros). Moreover, our output is hotels’ total sales levels, which is also measured in millions of euros. According to Hwang and Chang (2003), an estimation of such a production function incorporates all the factors of hotels’ production process (manpower, input materials, capital, machines, and equipment). These factors are needed to produce hotels’ intangible and tangible services, and they are reflected in the volumes of total sales. Furthermore, the adopted estimated production frontier provides us with the advantage of minimizing the dimensionality problems that can influence the estimated DEA-based productivity indices (Charles et al., 2019; Dyson et al., 2001; Wilson, 2018). Although we do recognize that multiple outputs are present, we lack detailed data on them, and, despite this fact, revenue efficiency and productivity change are what hotel management is really interested in.
For the purpose of our analysis, we utilize a sample of 270 hotels operating in the Balearic Islands over the period 2004-2013. The data have been extracted from AMADEUS database having the majority of the hotels operating in the regions of Palma (95 hotels), Eivissa (23 hotels), Calvia (22 hotels), and in the region of Santa Margalida (20 hotels). According to Orfila-Sintes et al. (2005), these regions are within the group of regions that form the main holiday destinations in Spain. Table 1 presents yearly the descriptive statistics of hotels’ inputs/output used in our analysis. Even though we are using a balanced panel over the period 2004-2013, for the purpose of our analysis we analyze our findings based on five subperiods that are determining the overall global financial crisis (GFC) phenomena. Following Fiordelisi et al. (2014), we analyzed the estimation of hotels’ productivity measures over five distinct periods. Specifically, we focused our analysis on the precrisis period (2004-2007) and then on the U.S. subprime crisis period (2007-2008). Moreover, we analyzed hotels’ productivity levels during the GFC period (2008-2010) and through the sovereign debt crisis period (2010-2012). Finally, hotels’ productivity levels during the postcrisis period (2012-2013) were examined.
Descriptive Statistics of the Factors of Hotels’ Production Function
Figure 1 presents the density plots from the order-

Density Plots of MPIα and Components During the Precrisis Period (2004-2007)
Moreover, Figure 2 presents our findings during the subprime crisis period (2007-2008). It is evident that for the case of α = 0.5 (top panel), the picture remains similar compared with the precrisis period. However, when we examined the case of α = 0.99 (bottom panel), our findings revealed that the components of the estimated productivity levels have a platykurtic distribution. This finding suggested that the estimated values of the productivity components are less concentrated around the mean, due to larger variations in the estimated components. This phenomenon is even more pronounced during the GFC period (Figure 3). Our findings suggested that the ability of hotels to operate at optimal scale, to catch-up, and to innovate (technological change) has been under pressure over the two examined periods.

Density Plots of MPIα and Components During the Subprime Crisis Period (2007-2008)

Density Plots of MPIα and Components During the Global Financial Crisis Period (2008-2010)
As a result of such a pressure, hotels’ productivity levels have been decreased (at least for the majority of the cases) during the sovereign debt crisis period (2010-2012). Figure 4 reveals such a decrease (case α = 0.99); however, and in contrast to the previous subperiod, we observed a counter reaction indicated by an increase in hotels’ scale efficiency and technological change levels. This was more pronounced during the postcrisis period (2012-2013), under which hotels’ abilities to operate at optimal sizes and produce innovative services (technological change levels) has been increased (Figure 5). Both findings are supportive of the study by Devesa and Peñalver (2013), signifying that the Spanish hotel industry is based on training technologies. These policies are reflected both on the observed technological change levels and also on the estimated scale efficiencies. Our findings are also in line with the study by Orfila-Sintes et al. (2005), providing evidence of high technological investment on tourist accommodation in the Balearics. Similar findings were reported by several other studies (Baidal et al., 2013; Cordero & Tzeremes, 2017; Garay & Canoves, 2011; Tzeremes, 2019) that referred to different Spanish destinations, emphasizing that during the GFC period the Spanish hotel industry has been resistant, following different restructuring strategies. Such strategies enable the Spanish hotel industry to adapt to the GFC challenges by increasing their ability to innovate and operate at optimal scale levels. The outcome of those strategies is pictured in our results, especially in the analysis of the hotels’ estimated

Density Plots of MPIα and Components During the Sovereign Debt Crisis Period (2010-2012)

Density Plots of MPIα and Components During the Postcrisis Period (2012-2013)
Finally, Supplemental Figure S2 (available online) presents the density plots of the estimated MPIα measures for four main regions. It is evident that between 2004 and 2013 the productivity levels measured with both values of α have been decreased. Regardless, the most productive region appears to be the region of Calvia. This is since the larger area of the estimated productivity densities lies to the right of the solid vertical line (i.e., unity). Our findings support those presented by Ortega and Chicón (2013) suggesting that hotels’ efficiency and productivity levels can be affected by different regional aspects.
Concluding Remarks and Policy Implications
The necessity for efficiency and productivity measures that are less sensitive to sample characteristics has been highlighted in the relative literature (Assaf & Josiassen, 2016; Assaf & Matawie, 2009; Assaf & Tsionas, 2018a, 2018b). This article, by applying quantile frontier measures (Daouia & Simar, 2007), uses the probabilistic framework of frontier estimation (Cazals et al, 2002; Daraio & Simar, 2005, 2007) to present robust (order-
Supplemental Material
sj-docx-1-jht-10.1177_1096348020974419 – Supplemental material for Productivity in the Hotel Industry: An Order-α Malmquist Productivity Indicator
Supplemental material, sj-docx-1-jht-10.1177_1096348020974419 for Productivity in the Hotel Industry: An Order-α Malmquist Productivity Indicator by Panayiotis Tzeremes and Nickolaos G. Tzeremes in Journal of Hospitality & Tourism Research
Footnotes
Authors’ Note:
We acknowledge the useful comments made by the reviewers. Also, we would like to thank Professor Albert G. Assaf for his helpful suggestions and comments.
Supplemental Material
Supplemental material for this article is available online.
References
Supplementary Material
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