Blockchain technology (BT) is widely implemented in businesses, yet its adoption within distinct channel leaderships in a supply chain has not been well studied. Following real-world practices, we build analytical models to study two strategies in which the manufacturer leads BT adoption (MLB) and the retailer leads BT adoption (RLB). Our results show that BT adoption does not necessarily create extra supply chain profits. Higher profits can be obtained when consumers show a strong preference for traceability or when the leader shares sufficient costs otherwise. Raising leaders’ cost-sharing proportions does not necessarily benefit followers, and the cost burden may motivate leaders to reduce the traceability level, thereby decreasing overall benefits. Interestingly, cost-sharing is not a “zero-sum” game for supply chain members, and sharing more costs as followers may help create mutual benefits. A comparison of the strategies of MLB and RLB reveals that the product price, traceability level, and carbon emissions in MLB can either be higher or lower than those in RLB. From an environmental perspective, we show that the carbon tax has a nonmonotonic effect on product retail prices. For the supply chain, it is possible to increase profits but simultaneously reduce emissions in each strategy, and a superior strategy that improves both economic and environmental performance exists. By modelling the regulator’s participation in BT adoption, we further show that emission taxes and BT subsidies are not concomitant, and surprisingly, we find that the emission tax may either increase or decrease with product emission intensity. Moreover, our extension shows that regular operational costs for BT may impact the economic performance of BT adoption but other key findings remain robust.

We consider dynamic competition between two platform-based products that exhibit two-sided network effects, such as game consoles and intelligent hardware. Firms compete in terms of pricing and Research & Development investment, which are driven by consumers' marginal utility of quality, indirect network effects, and the differentiation between consumers' preference for the products. We find that with a small marginal utility of consumers, the equilibrium investment of one firm increases first and decreases later with its product quality but is not obviously sensitive to the rival's. In contrast, with a large marginal utility, if the quality of the two products is comparable, the equilibrium investment increases substantially. However, if one product pulls ahead, the other firm will stop investing. Besides, we find that when the intrinsic value and the network value coexist, the market becomes more concentrated, even when consumers' marginal utility is small. The market concentration increases in both the consumers' marginal utility and the indirect network effect but decreases in the degree of differentiation between consumers' preference toward the two products. Interestingly, we show that differentiation plays an important role in shaping the market structure only when the network effect is weak. Counterintuitively, we show that the differentiation corrodes firms' total profits, which demonstrates that less fierce competition resulting from low substitution leads to a lower profit. Additionally, we reveal that dynamic interaction between quality and installed base motivates firms to improve from a low quality, the first-mover advantage does not ensure market dominance.

Under carbon tax regulation, we jointly measure the environmental and economic performances of three closed-loop supply chains, where remanufacturing is implemented through the reverse channels of retailer collection, manufacturer collection, and third-party collection. The equilibrium results for each supply chain are derived, and the impacts of emission-related factors are characterized. Through a numerical study, we explore the impacts of the emission intensities of both new and remanufactured products on the entire emissions. Additionally, the government’s policy concerning environmental protection is discussed. The results show that the collection rate and the first-period product quantity are piecewise monotonously related to the tax price and emission intensities. Either manufacturer collection or retailer collection can be the most eco-efficient reverse channel, while third-party collection is the least preferred. Retailer collection can be both environmentally and economically better off to achieve Pareto improvement. Otherwise, when manufacturer collection is the most eco-efficient reverse channel, it can be motivated by the government through subsidizing. Interestingly, numerical studies show that reducing the emission intensity of remanufactured products can be eco-efficient, while lowering the emission intensity of new products may harm the environment. In addition, with one subsidy, two tax prices can be set by the government, among which a higher tax price leads to better environmental sustainability.

The book explores optimal decisions for companies and government to develop a sustainable economy by applying established analytical models.

This chapter considers a supply chain consisting of a manufacturer and a retailer. The manufacturer sells its products through the retailer and an online platform and adopts green technology in the blockchain era. The platform can operate in marketplace mode or reselling mode. The network effect is considered to reflect the power of the platform to enlarge the potential market size. In the decentralized supply chain, the online platform encroaches on offline demand despite the same retail price. The increase in the network coefficient improves the abatement level and benefits the manufacturer and the platform but damages the retailer’s profit. For supply chain coordination, the abatement level with the reselling mode in the centralized supply chain is less than that in the decentralized supply chain if the network coefficient is high. Both marketplace mode and reselling mode can coordinate the supply chain if the network coefficient is low. Blockchain technology helps products become greener and brings more profits for the manufacturer and the platform. This induces supply chain coordination.

The tax price in a carbon tax regulation may vary from time to time. In this chapter, we model a manufacturer who produces new products in the first period and makes new and remanufactured products in the second period under carbon tax regulation where the tax price differs over the two periods. It is shown that improving the first-period tax price always decreases the total emissions, while improving the second-period tax price may increase the overall emissions. With the decrease in the remanufacturing emission intensity, the overall emissions could either increase or decrease. To effectively control the total emissions, the tax price could be raised selectively by the regulator according to the manufacturer’s production decision and the characteristics of remanufacturing. In addition, the subsidizing strategy for employing green technology during remanufacturing pays off in obtaining environmental benefits only when the original remanufacturing emission intensity is low enough. With this two-period tax regulation, regulators are enabled to improve both the economic and environmental benefits.

In modern manufacturing operations, green technologies are becoming increasingly popular. Meanwhile, trade-in programs are widely implemented to boost sales and enhance product recycling, which would benefit the environment. It is widely observed that many companies implement green technology (GT) and trade-in programs together. However, whether this act is always beneficial to the environment is unclear. We hence build analytical models to address this issue. To conduct a comprehensive study, we follow real-world practices and examine both the retailer collect (R-collect) and manufacturer collect (M-collect) scenarios in a supply chain. Our results show that the "R-collect scheme with GT" leads to the highest levels of supply chain profit and social welfare, but more emissions may be generated. In addition, implementing GT does not always benefit the environment in both R-collect and M-collect schemes. Considering from the environmental protection perspective, we interestingly show that governments should advocate the "M-collect with GT" and "R-collect without GT" schemes. Correspondingly, to motivate both the supply chain and consumers to accept the advocated strategies, we characterize the carbon tax and subsidy based "carrot-and-stick" policy. We further show that our main results hold when consumers are environmentally conscious.

This chapter investigates the optimal production and pricing decisions of a self-pricing manufacturer and the optimal cap-setting decisions of a regulator under cap-and-trade regulation. The objectives of the manufacturer and the regulator are to maximize profit and social welfare, respectively. We first derive the optimal joint production and pricing decisions and the corresponding total emissions of the manufacturer, with given parameters of the cap-and-trade regulation. Based on these results, we then solve the optimal cap of the regulator. In addition, we show the impacts of the emission intensity on the optimal total emissions and the optimal cap. Surprisingly, we find that both the optimal total emission and the optimal cap first increase and then decrease as the emission intensity increases.

We demonstrate a wavelength-tunable, sub-200 fs, and watt-level thulium-doped ultrafast fiber oscillator with a fundamental frequency repetition rate of 509.7 MHz. The wavelength can be tuned between 1918.5 nm and 2031 nm by adjusting the intra-cavity waveplates. When the wavelength is tuned to below 2000 nm, the average output power exceeds 1 W. The oscillator provides a maximum average power of 1.314 W (corresponding to a pulse energy of 2.58 nJ) and a highest peak power of 12.5 kW at 1940 nm. Such a high-power, tunable 2-µm mode-locked fiber laser is an ideal light source candidate for a variety of applications, such as frequency metrology, molecular spectroscopy, and ultrafast pump-probe spectroscopy.

We report a mode-locked high-power all-polarization-maintaining Er/Yb-doped large-mode-area fiber oscillator based on a bias nonlinear amplifying loop mirror (NALM). The oscillator can generate ∼1-nJ femtosecond pulses without dispersion compensation. By inserting a Martinez-type compensator to provide normal dispersion, it can generate >10-nJ picosecond dissipative solitons (DSs). The measured M2 factors are below 1.5, indicating a good beam quality. When the cavity dispersion is tuned to be ∼0.704 ps2, the oscillator can deliver chirped DSs with an average power as high as 690 mW at a repetition rate of 49.86 MHz, corresponding to a pulse energy of ∼13.8 nJ. The pulse after compression has a near Fourier-limited width of ∼2 ps. Successful demonstration of this laser provides a robust scheme for improving the performance of ultrafast fiber lasers in average power and pulse energy.

We report a compact, self-starting dispersion-managed mode-locked thulium-doped fiber oscillator that delivers 2.6 nJ pulses at 2 µm with a repetition rate of 250 MHz. The average output power and spectral bandwidth of the pulses reach impressive values of 648 mW and 103 nm, respectively. The generated pulses are near linearly chirped, capable of linearly compressing to 74 fs in a normal dispersion fiber after power attenuation. Using a nonlinear fiber compression scheme can even compress the pulses to 29 fs (4.3-cycle). The remaining pulse energy is 1.15 nJ, and the corresponding peak power is estimated as 39.4 kW. To the best of our knowledge, this is the first demonstration of nonlinearly compressing the pulse of a 2 µm fiber oscillator to the sub-5 cycle regime. Such a few-cycle fiber laser could be an ideal candidate source for short-wavelength mid-infrared frequency metrology and molecular spectroscopy applications.