Economic Bottleneck Research Articles

The First Strike Attempts in Republican History: The 1925 Telegraphers’ Strike

In the 19th century, with industrialization in the West, the modern concepts of labor and workers began to emerge. In fact, in many countries of the world, there had been some revolts and resistances in working life in earlier periods. However, the strikes carried out by workers to protect their rights in today's sense were the product of the industrialization that started in England. In the Ottoman Empire, the paid working class began to emerge in the second half of the 19th century, when the state's industrialization efforts intensified in the light of developments in the West. In this period, workers took different attitudes that showed their dissatisfaction with the problems they encountered in working life, but the strike movements took place in the last quarter of the 19th century. With the declaration of the Second Constitutional Era on July 23, 1908, workers' movements began to increase. Therefore, on August 9, 1909, the “Tatil-i Eşgal Law”, which is the strike and lockout law, was accepted in the Meclisi Mebusan (Parliament). Although strike movements did not completely disappear with the acceptance of the “Tatil-i Eşgal Law”, they largely decreased. Workers' movements experienced a period of stagnation from 1914 onwards due to the effects of war conditions. After the signing of the Armistice of Mudros on October 30, 1918, both the existing labor organizations established in 1908 and new labor organizations increased their activities. Consequently, the industrialization process that began in the West in the 19th century became a significant factor influencing labor movements and the protection of workers' rights. A similar process was experienced in the Ottoman Empire, however it developed under different conditions. With significant economic difficulties experienced throughout the country due to the destructive effects of World War I, The Armistice period was a challenging one for the Ottoman Empire. Owing to the long years of war and destruction, food stocks reached the point of depletion, and import routes were almost completely closed. This situation gave rise to a decrease in production in the Ottoman territories and a scarcity of consumer goods. Specifically, Istanbul felt these economic difficulties more intensively. The city faced both the direct impacts of the war and influxes of refugees. With the arrival of refugees, the population of Istanbul rapidly increased while resources gradually diminished. This deepened the economic bottleneck in the city even further. The scarcity of food and other essential commodities led to price increases and an increase in the activities of black marketeers. Black marketeers manipulated the economy by reaching scarce resources through illegitimate means and controlling prices. The situation was no different in Anatolia. War conditions negatively affected agricultural and production activities. The decrease in production naturally also affected exports negatively. Especially in many regions of Anatolia known for its agriculture-based economy, the quantity and quality of agricultural products decreased due to the war's effect. As a result, casualties were experienced both in the domestic market and in foreign trade. The Armistice period was also an economically challenging transitional period for the Ottoman Empire. Economic bottlenecks were experienced throughout the country due to the destructive effects of the war. During this period, not only Istanbul but also the entire country had to struggle with difficult economic conditions. The early years of the Republic of Türkiye marked an important period of transformation for the country. During this period, there was a restructuring of the state and intensified efforts towards modernization. However, the working class did not remain silent during this process. On the contrary, workers continued their activities through various associations and organizations to demand their rights. Workers demanding better conditions in the workplace attempted to make their voices heard by using effective tools such as strikes. Strikes became a common method that workers frequently resorted to defend their rights. Workers organized strikes to demand increases in wages, improvements in working hours, and better working conditions. One notable strike during the early years of the Republic was the attempted strike by telegraph workers in Adana, Samsun, and Trabzon in 1925. Although the strike fundamentally aimed to improve the wages and working conditions of telegraph workers, conflicting information provided by workers during the preparation of the strike's communication and text raised suspicions in Ankara. In this context, the chaotic environment in the country in 1925 led to the trial of telegraph workers who attempted the strike at the Ankara Independence Court.

Integrating solar electricity into a fossil fueled system

The power sector is a major contributor to carbon emissions in China, accounting for nearly half of all emissions, and therefore emission reductions from this sector will be critical, if China is to meet its 2060 targets. Deploying renewable energy sources is the most promising approach to decarbonizing the power sector. However, the intermittency and non-dispatchable nature of wind and solar power pose significant challenges to grid stability, particularly when these sources reach high penetration rates. During China's ongoing energy transition, coal-fired power units will be used to meet peak loads when solar and wind generation is not available. The economic and environmental implications of such a scenario are unclear. In light of this uncertainty, this study applies a unit commitment model to investigate the economic and environmental performance of load shaving strategies across different scenarios. Results show that, in the absence of energy storage systems, a solar penetration rate of 40 % will create an economic bottleneck, and high solar penetration would even increase the total carbon emissions of the whole power system. Moreover, the power system would choose to cycle the large thermal units first to accommodate the solar power, and start-stop strategy is subordinate.

To the Economy and Workers: Challenges and Opportunity

The rapid development of automation and new technologies over nearly two centuries has sparked heated discussions. Programmable, repetitive jobs are being replaced by technology, leaving large numbers of middle-skilled workers unemployable, and causing employment difficulties. But at the same time, the development of automation has created new employment opportunities for another group of laborers. Similarly, the development of automation once accelerated economic growth, but as the development of automation slowed down, economic growth encountered a corresponding bottleneck as well. In this paper, it is mainly used to refer to the historical development of literature research, analyze and summarize, so that the observed specific situation can be summarized. In addition, there are also descriptive studies, which generally describe the experience of the predecessors, play a revealing role, and further analyze and demonstrate. The research questions in this paper revolve around the economic and workforce implications of advances in automation. The source of this thinking is that automation replaces labor, resulting in a large number of middle-skilled workers being unemployed and abandoned by the market because they do not have the ability to use new technologies. This group has a huge base in society, and improving this situation will help reduce poverty, break through the economic bottleneck. The conclusion of this paper is that workers need to improve their competitiveness in the market, and the government needs to adjust policies to adapt the labor force to the market, and that the market is close to meeting the employment needs of the labor force.

Technological strategies for managing sugarcane vinasse in two-stage biodigestion plants: Energetic and economic aspects

Anaerobic digestion is recognizably the most efficient approach (on both energetic and environmental bases) to manage sugarcane vinasse in ethanol-producing plants. In particular, separating the fermentation from methanogenesis (two-stage schemes) step improves the process by providing higher stability to methanogens. Based on experimental data, this study compared the techno-economics of different operating strategies for the two-stage biodigestion of sugarcane vinasse: biohydrogen exploitation, non-recovery of biohydrogen and removal of sulfate (fermentation) coupled to two alkalinization approaches in methanogenesis (NaHCO3 dosing or NaOH dosing + liquid phase recirculation). Potential biogas uses included the production of electricity, purified biohydrogen or biomethane. Removing sulfate during the fermentation increased the energy yield of biodigestion by over 30% (peaking at 914 TJ when producing biomethane), a 5-fold higher level than exploiting biohydrogen (contribution of 25.3 TJ). However, the non-optimized dosing of chemicals still represents the main economic bottleneck of the process, nullifying the aforementioned energy gains. Replacing NaHCO3 dosing in the sulfidogenic-fermentative reactors by recycling the bicarbonate produced during methanogenesis coupled to minimizing the inputs of NaOH in the methanogenic units provided the best economic performance: internal rates of return of 21.6% (electricity production) and 28.9% (biomethane production towards diesel replacement). The highly efficient production of electricity using the combined cycle represents an attractive alternative for exploiting the vinasse-derived biogas in a short-term time horizon, whilst maximizing the economic exploitation of biomethane was found to directly depend on the replacement of diesel. Overall, exploiting the biogas produced from vinasse is profitable; however, the maximization of gains depends more on a rational use of chemicals than on more efficient methane evolution rates.

Fused Deposition Modeling 3D Printing in Oral and Maxillofacial Surgery: Problems and Solutions.

Three-dimensional (3D) printing technology in medicine is one of the new and innovative technology for fabricating 3D models of complex anatomical structures that can be observed both visually and haptically. Patient-specific 3D models fabricated through this process are currently being used for various purposes, including surgical simulation, training, and medical education. Most of the personal use/low-end desktop 3D printers that are becoming widespread are fused deposition modeling (FDM) 3D printers. Compared to professional/high-end 3D printers, the price of the personal use/low-end desktop FDM 3D printer itself, filament, and running costs are lower; it can lower the economic bottleneck for introducing 3D printing technology into clinical practice, such as surgical simulation. With a desktop FDM 3D printer and a general-purpose PC, anyone can now rapidly fabricate 3D models on their own without having to rely on 3D printing labs and specialized technicians. However, it is also true that FDM 3D printers, due to their mechanical characteristics, encounter many difficulties and problems that emerge during the 3D printing process. Knowledge, know-how, and tips about FDM 3D printers have been introduced in various media, and it has become easy to know about them worldwide via the Internet. However, there has been no comprehensive technical review to date to produce osseous 3D models for use in oral and maxillofacial surgery. In this report, to create 3D models according to the characteristics of maxillofacial and oral surgery, we enable surgeons themselves to create 3D models smoothly by presenting ideas for CT scanning, points to note when exporting Digital Imaging and Communications in Medicine (DICOM) image data, how to create optimal stereolithography (STL) models, and problems and solutions for 3D printing.

Potential of the sewage sludge valorization in Scandinavia by co-digestion with other organic wastes: A techno-economic assessment

The aim of this study was to compare the techno-economic feasibility of five different scenarios to valorize sewage sludge in co-digestion with another organic waste. The first three scenarios were based on real full-scale processes in Scandinavia, furthermore two original biorefinery scenarios for carboxylates and biogas production were proposed. Data from the actual plant of one scenario was used in order to calibrate the simulation, creating five realistic models for sludge valorization. Two downstream technologies were simulated for the valorization of carboxylates: anion exchange chromatography and biological separation (through PHA production). Even though none of the models was profitable without subsidies, the biorefinery scenario with biological separation was the most promising one, with the operating costs (2.79 million €) closest to the total revenues (0.8 million €). The use of anion exchange chromatography created an economic bottleneck in the model (57% of the operating costs), suggesting the need for more simple and cost-effective downstream technologies, when developing biorefineries for the valorization of waste streams. Moreover, the importance of public subsidies, gate fees for organic wastes and the amount of treated material were found to be key aspects for the economic feasibility of these facilities treating waste, increasing the total revenues between 2 and 15 times, depending on the modelled scenario.

Food for Thought: The Protein Transformation

Food for Thought: The Protein Transformation

Biotransformation of oleochemical industry by‐products to polyhydroxyalkanoate bioplastic using microbial fermentation: A review

AbstractFor many decades, global efforts have been attempted to replace the petrochemical plastics with biodegradable and environment friendly plastics. The petrochemical plastics that require many years to decompose have profound consequences on the environment. A natural, biodegradable, and plastic‐like polymer, polyhydroxyalkanoate (PHA), has been extracted from and synthesized by microbes, particularly bacteria. However, the prospective large‐scale production of PHA faced an economic bottleneck for less production costs. Research has thus shifted to one of the most common alternatives, which is the utilization of less costly raw materials or carbon sources that include industrial by‐products and wastes, such as glycerine pitch and glycerol. This review elucidates the discovery, basic mechanisms, and applications of PHA, as well as provides insights regarding the importance of PHA conversion from glycerine pitch and glycerol. This review also summarizes some possible future modifications to improve the efficiency of glycerine pitch and glycerol as carbon sources in PHA production. The conversion endeavors of wastes to a valuable product, PHA, that not only reduces petrochemical plastic pollution, waste generation, and PHA production costs but also supports economic and resource sustainability, which ultimately further progress towards the cradle‐to‐cradle design and circular bioeconomy concept.

Mitigating the negative impact of soluble and insoluble lignin in biorefineries

The presence of inhibitors is still an economic bottleneck that needs to be resolved in order to make the biorefineries feasible, requiring the development of technologies capable of improving their competitiveness in the biofuel marketplace. Soluble and insoluble lignin can impair the enzymatic hydrolysis process by inhibition, deactivation, and unproductive adsorption of enzymes. Washing the pretreated biomass or using lignin-blocking additives during saccharification could mitigate these negative effects in future biorefineries. Here, an investigation was performed of the combined mitigation processes, in terms of their technical and economic feasibility in an integrated first and second generation (1G2G) sugarcane biorefinery. Evaluation was made of the impacts of biomass washing and soybean protein addition, separately or in combination, on glucose yields for enzymatic hydrolysis in the presence of high (liquor) and low (buffer) concentrations of soluble inhibitors/deactivators. Combining washing and soybean protein addition provided the highest glucose yields, with an increase of up to 50%. The effect of the mitigation processes could be explained by a combination of catalytic mechanisms acting on both soluble and insoluble lignin. In an industrial context, biomass washing (90 °C, 15% (w/w) solids, 3 steps) followed by soybean protein addition (12% (w/v) solids) provided a cost-competitive methodology for bioethanol production, with an estimated net present value of US$ 9.16 × 107, optimizing hydrolysis process in the 1G2G sugarcane biorefinery.

Sustainable production of ammonia fertilizers from biomass

AbstractNitrogen is the most limiting plant nutrient. Inexpensive natural gas has substantially reduced costs of ammonia fertilizer for intensive agriculture in the developed world, but its excessive use negatively impacts downstream ecosystems. By contrast, the availability of ammonia fertilizer is a major economic bottleneck for agriculture in developing countries. A dedicated lignocellulosic biomass crop could supply sufficient substrate to generate optimal nitrogen fertilizer on less than 5% of a grower's food crop acreage. Reimagining ammonia generation using biomass could significantly enhance sustainable agricultural productivity in developing countries when combined with emerging catalytic technologies. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd

Experiment Study on Small Leak Detection and Diagnosis for Propulsion System Pipelines of Sounding Rocket

The small leak in the propulsion system pipeline of the sounding rocket is prone to occur in the connections because of the screw thread loosening. Due to economic and technical bottleneck, the traditional soap bubble method is widely used in practice to evaluate whether existing a leak or not by visually observing the bubble’s size and numbers. Thus doing so will result in the low inspection efficiency and high cost. Using acoustic emission (AE) techniques, this paper presents an experimental study on small leak detection on the screw thread connection in the propulsion system pipeline of sounding rocket. The time and frequency characteristics of the corresponding small leak AE signals are investigated. After characteristic indices extraction and selection, the multi-class support vector machines (MCSVM)-based leak rates recognition algorithm in One–vs–All (OVA) is proposed. It has been validated that, for the propulsion system pipeline of the sounding rocket, the dominant characteristic frequency band of the small leak AE signals induced by screw thread loosening concentrates on 35–45 kHz. The proposed optimal OVA SVM models can achieve good classification accuracy of >98% by using the characteristic index set {Envelope area, standard deviation (STD), root-mean-square (RMS), Energy, Average frequency} and Gaussian Radial Basis Function (RBF) kernel function. The drastic drops in the false alarm attribute to use the combination of time- and frequency-domain characteristic indices. Especially, once adding the “Envelope area” into the characteristic index set, the classification accuracies of the OVA SVM models are further improved significantly regardless of the effect of kernel functions.

Green Synthesis and Electrochemical Study of Cobalt/Graphene Quantum Dots for Efficient Water Splitting

Hydrogen production via electrochemical water splitting is limited thermodynamically by the sluggish oxygen evolution reaction (OER) at the anode. The use of noble metal-based catalysts leads to an economic bottleneck because of the high cost associated with such materials. This article is an electrochemical investigation of an economically viable and advanced OER catalyst made of cobalt/graphene nanocomposite quantum dots (QDs). A series of characterization techniques, such as high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and fluorescence measurements, were performed, and they confirmed the formation of graphene QDs as well as the formation of cobalt-based QDs. A very high current density of 43.16 mA cm–2 was observed for the QD nanocomposite, whereas smaller current densities were seen for Co nanoparticles (21.1 mA cm–2) and a benchmark Pt/C commercial catalyst (5.99 mA cm–2). Furthermore, an overpotent...

Proof of concept for the simplified breakdown of cellulose by combining Pseudomonas putida strains with surface displayed thermophilic endocellulase, exocellulase and β-glucosidase.

BackgroundThe production and employment of cellulases still represents an economic bottleneck in the conversion of lignocellulosic biomass to biofuels and other biocommodities. This process could be simplified by displaying the necessary enzymes on a microbial cell surface. Such an approach, however, requires an appropriate host organism which on the one hand can withstand the rough environment coming along with lignocellulose hydrolysis, and on the other hand does not consume the generated glucose so that it remains available for subsequent fermentation steps.ResultsThe robust soil bacterium Pseudomonas putida showed a strongly reduced uptake of glucose above a temperature of 50 °C, while remaining structurally intact hence recyclable, which makes it suitable for cellulose hydrolysis at elevated temperatures. Consequently, three complementary, thermophilic cellulases from Ruminiclostridium thermocellum were displayed on the surface of the bacterium. All three enzymes retained their activity on the cell surface. A mixture of three strains displaying each one of these enzymes was able to synergistically hydrolyze filter paper at 55 °C, producing 20 μg glucose per mL cell suspension in 24 h.ConclusionWe could establish Pseudomonas putida as host for the surface display of cellulases, and provided proof-of-concept for a fast and simple cellulose breakdown process at elevated temperatures. This study opens up new perspectives for the application of P. putida in the production of biofuels and other biotechnological products.Electronic supplementary materialThe online version of this article (doi:10.1186/s12934-016-0505-8) contains supplementary material, which is available to authorized users.

INVect - a novel polycationic reagent for transient transfection of mammalian cells

Background For rapid recombinant protein production in small to medium size volumes, transient transfection of mammalian cells is still the method of choice in biotechnology [1]. However, due to the high costs of commercially available lipofectamines or polycationic transfection reagents such as polyethylenimine (PEI), the most widely used transfection reagents available present a substantial economic bottleneck. While these reagents produce seemingly high transient transfection rates [2], there is still a strong desire for transfection reagents providing both secure and easy handling and higher recombinant protein production. As part of our commitment to excellence, InVivo BioTech Services initiated a joint venture with emp Biotech and developed a novel polycationic reagent, named INVect, for transient transfection and recombinant protein production in mammalian cells.

Technology Focus: CO2 Applications (July 2013)

Technology Focus Research-and-development modeling has shown that CO2 can diffuse a small distance into the thick shale caprocks above brine aquifers used for sequestration and cause migration of siderite (iron carbonate), magnesite (magnesium carbonate), calcite, and other precipitates back into the target zone, which is what is wanted for mineral sequestration of CO2. I bring this up because, eventually, the industry may want to enhance the oil recovery from fractured shale oil (e.g., Bakken, Niobrara, and Monterey). A keynote speaker at the 2013 SPE Unconventional Reservoir Conference in The Woodlands, Texas, suggested that the industry may eventually want to improve recovery of the Bakken by waterflooding. CO2 might also be an enhanced-oil-recovery direction for shale oil and effect a dual benefit of storage of CO2. Shale (and other mudstones) has significantly more mineral components with iron and other metals (e.g., clays and pyrite) than do typical clastic and carbonate oil reservoirs. As a result, the geochemical reactions and adsorption will be more complex than the typical CO2 floods have shown over the last 30-plus years. A university laboratory effort was published in this focus area in 2011 and also in the SPE Journal on using organic-rich shale for CO2 storage. Today, reservoir simulators are robust and give the user great comfort in predicting how recovery performance will be affected by CO2 injection and, to a limited degree, geomechanical alterations. However, the industry currently has no functional true 3D reactive transport simulator that can help engineers efficiently model the CO2 flooding in shale where geochemical reactions and thermodynamic phase transitions take place simultaneously. Reservoirs that have rock assemblages consisting of a few mineral components have been modeled to a limited degree but are difficult to simulate beyond a teaching/research-and-development level. Very few truly reactive transport reservoir simulators exist. The few reactive reservoir simulators that are available are fairly good at 1D, possibly 2D, models but fail as a fast robust general engineering tool when large mineral assemblages with large orders-of-magnitude differences in kinetic reaction rates are to be modeled in three dimensions. A fast reactive transport simulator tool will need to be in place for engineering purposes for CO2 storage, as well as for EOR engineering studies, in shale. As an additional side note, the 2014 US president’s budget submitted to the US Congress has cut the carbon-storage program by approximately 47% but has increased the carbon-capture research side of the program (by approximately 43%), which is the economic bottleneck of the carbon capture, utilization, and storage process, especially for power plants. Whether the US Congress will go along with this is yet to be determined because there is some opposition, especially from congress members from coal states. Recommended additional reading at OnePetro: www.onepetro.org. SPE 157136 Evaluating a Depleted Oil and Gas Field in the East Coast of Trinidad for Disposal of Carbon Dioxide by D.J. Jaggernauth, Petrotrin SPE 156983 Enhanced CO2 Storage in Deep Saline Aquifers by Nanoparticles: Numerical-Simulation Results by Harpreet Singh, The University of Texas at Austin, et al. SPE 157396 Sustainable Production of Biochemicals and Biofuels Based on Biofixation of Carbon Dioxide by Microalgae by W.A.P. van den Bos, TNO, et al.

Brazil’s energy divide: sustainable energy alternatives for the brazilian amazon region

The insertion of the Brazilian Amazon region into the Brazilian and global economies is one of the challenges faced by the Brazilian economy. Accounting for 60% of the Brazilian territory, the region will play a key role in shaping the future growth and development of the Brazilian economy in the next decades. Energy availability has been the region’s main economic bottleneck. The energy divide refers to the lack of adequate and reliable energy supply in the Amazon region and constitutes the region’s main barrier for its further economic development and growth. The lack of energy imposes limitations on the local population standards of living, increases the business costs, limits the economic exploration, and limits its business vocations. The region’s energy matrix carries a substantial carbon footprint, since most of the region’s energy needs are fi lled by fossil fuels. This paper discusses energy solutions and alternatives for the Brazilian Amazon region.

Seesaw in the air: Interconnection regulation and the structure of mobile tariffs

Interconnection rates are a key variable in telecommunications markets. Every call that is placed must be terminated by the network of the receiving party, thus the termination end has the characteristic of an economic bottleneck and is subject to regulation in many countries. This paper examines the impact of regulatory intervention to cut termination rates of calls to mobile phones. We argue that regulatory cuts should have a differential impact according to the type of tariff the mobile customer subscribes to. While all mobile customers may pay higher prices because of a “waterbed” effect, termination rates also affect competition among mobile operators. We show that the waterbed effect is diluted, but not eliminated, for customers with pre-paid cards, where regulation also acts as impediment to “raise-each-other’s-cost” collusive strategies that mobile networks can adopt. The waterbed effect is instead strongest for consumers with post-paid subscription contracts.

Hemicellulases and auxiliary enzymes for improved conversion of lignocellulosic biomass to monosaccharides

BackgroundHigh enzyme loading is a major economic bottleneck for the commercial processing of pretreated lignocellulosic biomass to produce fermentable sugars. Optimizing the enzyme cocktail for specific types of pretreated biomass allows for a significant reduction in enzyme loading without sacrificing hydrolysis yield. This is especially important for alkaline pretreatments such as Ammonia fiber expansion (AFEX) pretreated corn stover. Hence, a diverse set of hemicellulases supplemented along with cellulases is necessary for high recovery of monosaccharides.ResultsThe core fungal cellulases in the optimal cocktail include cellobiohydrolase I [CBH I; glycoside hydrolase (GH) family 7A], cellobiohydrolase II (CBH II; GH family 6A), endoglucanase I (EG I; GH family 7B) and β-glucosidase (βG; GH family 3). Hemicellulases tested along with the core cellulases include xylanases (LX1, GH family 10; LX2, GH family 10; LX3, GH family 10; LX4, GH family 11; LX5, GH family 10; LX6, GH family 10), β-xylosidase (LβX; GH family 52), α-arabinofuranosidase (LArb, GH family 51) and α-glucuronidase (LαGl, GH family 67) that were cloned, expressed and/or purified from different bacterial sources. Different combinations of these enzymes were tested using a high-throughput microplate based 24 h hydrolysis assay. Both family 10 (LX3) and family 11 (LX4) xylanases were found to most efficiently hydrolyze AFEX pretreated corn stover in a synergistic manner. The optimal mass ratio of xylanases (LX3 and LX4) to cellulases (CBH I, CBH II and EG I) is 25:75. LβX (0.6 mg/g glucan) is crucial to obtaining monomeric xylose (54% xylose yield), while LArb (0.6 mg/g glucan) and LαGl (0.8 mg/g glucan) can both further increase xylose yield by an additional 20%. Compared with Accellerase 1000, a purified cocktail of cellulases supplemented with accessory hemicellulases will not only increase both glucose and xylose yields but will also decrease the total enzyme loading needed for equivalent yields.ConclusionsA diverse set of accessory hemicellulases was found necessary to enhance the synergistic action of cellulases hydrolysing AFEX pretreated corn stover. High glucose (around 80%) and xylose (around 70%) yields were achieved with a moderate enzyme loading (~20 mg protein/g glucan) using an in-house developed cocktail compared to commercial enzymes.

Seesaw in the Air: Interconnection Regulation and the Structure of Mobile Tariffs

Interconnection rates are a key variable in telecommunications markets. Every call that is placed must be terminated by the network of the receiving party, thus the termination end has the characteristic of an economic bottleneck and is subject to regulation in many countries. This paper examines the impact of regulatory intervention to cut termination rates of calls to mobile phones. We argue that regulatory cuts should have a differential impact according to the type of tariff the mobile customer subscribes to. While all mobile customers may suffer because of a “waterbed” effect, termination rates also affect competition among mobile operators. We show that the waterbed effect is diluted, but not eliminated, for customers with pre-paid cards, where regulation also acts as impediment to “raise-each-other’s-cost” collusive strategies that mobile networks can adopt. The waterbed effect is instead strongest for consumers with post-paid subscription contracts.

Economic analysis of production bottlenecks

The management of bottlenecks has become a central topic in the planning and control of production systems. In this paper, we critically analyze bottlenecks from an economic perspective. Using a queueing network model, we demonstrate that bottlenecks are inevitable when there are differences in job arrival rates, processing rates, or costs of productive resources. These differences naturally lead to the creation of bottlenecks both for facilities design and demand planning problems. To evaluate bottlenecks from an economic perspective, we develop the notion of an “economic bottleneck,” which defines resources as bottlenecks based on economic, rather than physical, characteristics.