## 3 Data and Results
### Results
#### 3.2.2 Efficiency and Technology Change Analysis
Oppo is entering the global market through strong efficiency improvements, i.e., improved price/performance ratio, which itself identifies productivity gains through technological advances. Motorola maintained the status quo until 2018, but the evaluation of edge+ released in 2019 recognized the improvement of cost-performance ratio in the global market, and it is evaluated that there was technological progress compared to Motorola's own products. Looking at the accumulated results, LG seems to be in a normal situation overall, but it seems to be an optical illusion in 2019 following a large productivity decline over the two years of 2016-2018. Huawei maintains its position in the global market with efficiency improvement as its main strength. Apple is trying to improve productivity through technological advances, but in the global market, efficiency was assessed as temporarily regressing in 2020. Figure 3 compares average productivity, efficiency, and technological change before and after 2017. Figure 3a is a graph showing the efficiency change and technological change before and after 2017. The red arrow indicates that both the efficiency change and the technological change have regressed, the blue color indicates the progress, and the dotted line indicates that any one has advanced or regressed. Huawei is the only company that has advanced in both technological change and efficiency change. On the other hand, Vivo and Apple have regressed in both efficiency changes and technological changes. Further research is needed to interpret the cause. In other words, if the price of a product is lowered, the change in efficiency can be larger, and if the product's technology level is already high, the price of the product can be higher. Although the average degree of technological change and efficiency change decreased, it was found that there was a difference in the degree depending on the smartphone. Figure 2: Mean efficiency and technology changes for the period of 2013–2020: (**a**) MPI; (**b**) Global MPI. Figure 3: _Cont_. Notably, the companies that achieved productivity gains compared to before 2017 were Huawei, Oppo, and Motorola. The companies that achieved the efficiency improvement were Huawei and Xiaomi. Companies that achieved technological advances were Huawei, Motorola, and Oppo. Apple, Vivo, and Sony have largely gone backwards compared to SOA. In the Malmquist analysis, only the global Malmquist productivity index, which satisfies transitivity, was analyzed, and thus there is a limit in drawing conclusions about the company's product differentiation strategy. However, the dynamic aspects of technological change and efficiency change of companies contributing to the global production frontier can be confirmed. Figure 4 is a graph showing the changes in productivity, efficiency, and technology by year for major brand companies. Chinese companies such as Xiaomi, Oppo, Vivo, and Huawei are trying to improve productivity through technological advances while maintaining high efficiency in terms of price/performance. Samsung is characterized by dynamics in which technological change, efficiency change, and productivity change are integrated and elastically. Apple maintains a stable level of technological change, while efficiency changes are driving the dynamics. Motorola and LG, which have market influence in the North American market, have in common that they have stable efficiency changes, but while Motorola is maintaining stable technological changes, LG has large fluctuations. Sony has been regressing in technological change since 2018, and it is interested in how much it will maintain the driving force of technological progress achieved during 2015-2017. Figure 3: Comparison of productivity changes by period using global MPI: **(a)** transition of technology change and efficiency change. The figure is displayed in the form of “Company name year, efficiency change, technological change”.