Network Investment and Competition with Access-to-Bypass

This paper examines firms' incentive to make irreversible investments under an open access policy with stochastically growing demand. Using a simple model, we derive an access-to-bypass equilibrium. Analysis of the equilibrium confirms that the introduction of competition in network industries makes a firm's incentive to make investments greater than those of a monopolist. We then show that a change in access charges induces a trade-off in social welfare. That is, a decrease in the access charge expands a social benefit flow in the access duopoly, and deters not only the introduction of a new network facility, but also a positive network externality generated by the construction of an additional bypass network. The feasibility of the socially optimal investment timing is then discussedOpen access policy, Investment, Real options, Network facility, Access charge

Gradual Network Expansion and Universal Service Obligations

Universal service obligations are usually not competitively neutral as they modify the wayfirms compete in the market. In this paper, we consider a continuum of local markets in a dynamic setting with a stochastically growing demand. The incumbent must serve all markets (ubiquity) possibly at a uniform price and an entrant decides on its market coverage before firms compete in prices. Connecting a market involves a sunk cost. We show that the imposition of a uniform price constraint modifies the timing of entry: for low connection cost markets, entry occurs earlier while for high connection cost markets, entry occurs later.

Delegating Infrastructure Projects with Open Access

This paper provides a simple model that examines a firmfs incentive to invest in a network infrastructure through coalition formation in an open access environment with a deregulated retail market. A regulator faces a dilemma between inducing an incentive for efficient investment and reducing the distortion generated by imperfect competition. We show that, in such a case, the degree of cost-reducing effect of the investment is crucial from a welfare point of view. In particular, when network investment through coalition formation creates a large (small) cost-reducing effect, the regulator can (should not) delegate an investment decision to firms with an appropriate level of access charge.Network infrastructure, Coalition, Access Charge, Delegation

Gradual Network Expansion and Universal Service Obligations

Universal service obligations are usually not competitively neutral as they modify the way firms compete in the market. In this paper, we consider a continuum of local markets in a dynamic setting with a stochastically growing demand. The incumbent must serve all markets (ubiquity) possibly at a uniform price and an entrant decides on its market coverage before firms compete in prices. Connecting a market involves a sunk cost. We show that the imposition of a uniform price constraint modifies the timing of entry: for low connection cost markets, entry occurs earlier while for high connection cost markets, entry occurs later

Network Formation with Access Prices : A Failure of Forward-Looking Rules

ネットワーク型公益事業におけるネットワーク不可欠設備の設備使用料である接続料金は,有効かつ公正な競争環境を創出するための重要な要因である.その接続料金の設定における長期増分費用ルールは,将来の技術進歩を見込んだ最も効率的な技術のもとでの接続費用に基づいて接続料金を設定する方法であるが,それは現実の電気通信市場における接続料金設定ルールとして幾つかの国で採用あるいは検討されている.しかし,この長期増分費用ルールの採用については賛否両論がある.本稿では,提携形成に関する非協力ゲーム・モデルを用いて,長期増分費用ルールが接続料金設定ルールとして採用された場合,生産費用削減のための効率的な企業間提携が形成されないことを示す.その意味で,長期増分費用ルールは経済厚生の点から見てマイナスの効果を持つことを指摘する.A forward-looking (cost) rule is a principle that involves the use of near-term best-practice technology and efficient engineering, rather than current available technology. In this paper, we present a drawback of the forward-looking access-pricing rule whereby firms are allowed to form a coalition in order to reduce thenproduction cost by a joint research venture, or by construction of a common network facility. We show that firms do not have sufficient incentive to form an efficient coalition when the access-pricing rule requires the access charge to be set lower than its current access cost

Osteoblast-derived vesicles induce a switch from bone-formation to bone-resorption in vivo

Bone metabolism is regulated by the cooperative activity between bone-forming osteoblasts and bone-resorbing osteoclasts. However, the mechanisms mediating the switch between the osteoblastic and osteoclastic phases have not been fully elucidated. Here, we identify a specific subset of mature osteoblast-derived extracellular vesicles that inhibit bone formation and enhance osteoclastogenesis. Intravital imaging reveals that mature osteoblasts secrete and capture extracellular vesicles, referred to as small osteoblast vesicles (SOVs). Co-culture experiments demonstrate that SOVs suppress osteoblast differentiation and enhance the expression of receptor activator of NF-κB ligand, thereby inducing osteoclast differentiation. We also elucidate that the SOV-enriched microRNA miR-143 inhibits Runt-related transcription factor 2, a master regulator of osteoblastogenesis, by targeting the mRNA expression of its dimerization partner, core-binding factor β. In summary, we identify SOVs as a mode of cell-to-cell communication, controlling the dynamic transition from bone-forming to bone-resorbing phases in vivo.Uenaka M., Yamashita E., Kikuta J., et al. Osteoblast-derived vesicles induce a switch from bone-formation to bone-resorption in vivo. Nature Communications 13, 1066 (2022); https://doi.org/10.1038/s41467-022-28673-2