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Thursday, December 30, 2010

One Day Walking along the Freedom Trail

With Boston's favorite bakery- Mike's Pastry(北京的同学们,就和稻香村似的,连点“菜”方式都一样), I started my own freedom trail trip. Starting from Haymarket. Today the mood of overlooking the other side of sea haunted me, I am kind of homesick. The joy of walking alone on the street can be described the saying "只要心是自由的, 没有到不了的地方。"(you can fly with the free mind)

 Here Buried Franklin 

Backyard of the Old North Church- HOPE

View from Charlestown Bridge 

 Sailing Mood
 How are you in the other side of earth?

Copp's Hill Burying Ground

Bunker Hill Monument
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@ USS Constitution

Hilarious Commercial Board
OUCH!!!!!

Way back home. 

sunset when I went back. @ the Charlestown Bridge

Finally I got home and have a taste of this piece of delicious. 


Sunday, December 12, 2010

Telecommunication Network Access Pricing Under Vertical Integration


When you make a long-distance phone call, it has to go through the local exchange carrier's local loop, switches, transmission facilities at both originating and terminating ends and through a trunk line in between the two points. Since the breakup of AT&T in 1984, competition in long-distance market has become a normal pattern in telecommunication industry. However, incumbent in the local markets with the essential facilities like local loop, or more precisely the very last mile form the local exchange to the end-user's home, has a major market power in the market.  Entrants in the long distance market have to pay access fee to get access to the local network to originate and terminate a call. 

Under vertical separation, bottleneck suppliers don't compete with the entrants in the long-distance market. The competition degree of the downstream market plays a important role in determine the market efficiency. Under vertical integration, incumbents share the long distance market with new entrants by providing them access to local network. They have to consider the tradeoff between retail sales to end-users and access fee gain from entrants when they set the access fee. Normally, there are four pricing rules of access fee, ECPR, Ramsey Pricing, Cost-based pricing and Global price caps.

 I. ECPR(Efficient Component Pricing Rule)
Access price is set equal to marginal cost of access plus the opportunity cost of access. The opportunity cost of access is the forgone profit contribution by selling access to downstream rather than selling to retail end-users. Here we assume the customer only subscribe one carrier.
               Pa=MCa+Copp= P1-C1. 
Here P1 is long-distance price of incumbent, C1 is the long-distance marginal cost of the incumbent. 
ECPR is relatively simple and it ensures that only entrance who can undercut the incumbent will enter. Also, "entry is neutral regarding operating profit for the incumbent", so it won't have incentive to destroy the entrants by predatory pricing, which is a potential problem of global price cap. However, just because the ECPR rule is simple, it is not suitable when products or services are differentiated. 

II. Ramsey Pricing
When maximize social welfare under the participation constrain, we can always get Ramsey pricing outcome. The mark up of local call prices, incumbent long-distance calls and entrants' long-distance calls are all obey the inverse elasticity rule. Here we use superelasticities to include the substitution and complementarity among different calls. The optimal access price under Ramsey pricing is composed of two parts, which are the standard Ramsey pricing equation and the substitution effect of the incumbents' sales of local network and their loss of retail sales. 

a = 2C0 + λ/(1+ λ)(p2/ε2) + δ(p1 – 2C0 – C1)   (Armstrong, Doyle and Vickers, 1996) 

Also, 2C0 +  δ(p1 – 2C0 – C1)  is called sophisticated ECPR.  δ here is a displacement ratio, which expressed the reactions of competitors. It is the ratio of quantity reaction of incumbent to the price change of entrant's long-distance call price and quantity reaction of entrances. Sometime, we call it business-stealing effect. When δ =1, Pa= P1-C1, the simple ECPR. 

The universal drawback of Ramsey pricing is that the requirement of information is high, and the computational burden is heavy.

III. Cost Based Pricing- Long-run Incremental Cost Pricing( LRIC Pricing)

IV. Global Pricing Cap
Global pricing cap is a price cap includes the access pricing into the multi-product price cap. It treats access product as one of the whole products into regulation. Under this method, if regulator can assign an idealized or perfect weight to the price cap which can lead to all product pricing at Ramsey pricing. Then the global pricing cap give a more flexible way for firms to reach the optimal pricing. However, just as we said, to calculate the optimal quantity weight is an ideal idea, which requires full information. Therefore, as a good theoretical method, global pricing cap never implemented. Moreover, applying a price cap may in a way enhance the incentive of incumbent to introduce the predatory pricing strategy. The local exchange carriers might set a price below the marginal cost to get rid of competition in the first stage, and recoup the revenue from monopoly pricing later. 

All of the above four access pricing method is designed for ONE WAY ACCESS situation, we will discuss later about two-way access and other topics in network industry regulation.






Friday, December 10, 2010

Ratchet Effect

Ratchet effect is an effect when we discuss about regulation lag or the issue raised when we talked about commitment problems.  Any finite contract with asymmetric information actually might exhibit the ratchet effect.

For example, under Bayesian mechanism, regulator at first only know the information of regulated firms based on the distribution information. At stage one, if there is two options, a high power incentive and a low power incentive, regulated firms will automatically choose the one favored to themselves and as a result reveal the type of the firm. Self-selection is an important feature of bayesian mechanism. At stage 2, usually when the first contract expires, regulator can use the information of firms' ex post cost to reset the firm's prices. Without commitment, firms are in a situation of " punished by doing well in the last period." If firms know about this mechanism they will have a less incentive to engage in cost reducing effort.  It can leads to a series of problems, less investment, cost inflation, etc.

What if there is a commitment of the regulator of not changing the contract for a relatively long period (which still has the ratchet effect in the last period). It can reduce the above problems, but as all long-term contracts it have the problem of inflexibility . In a world changed almost every second, a fixed contract can not probably deal with the turmoil, say policy and technology changes. Not to mention the unredeemed promise. In a regulatory world, we can't just say, hey, don't cry for the pouring milk. We have to correct the mistakes.

Joskow mentioned in "Regulation of natural monopolies"that "the behavior of a firm will depend on the information that its behavior reveals to the regulator ex post and how the regulator uses that information in subsequent regulatory reviews." It is a game between the regulator and regulated firms. When there is no commitment, we can analysis the situation happened from both sides' behavior. He cited the UK's RPI-X mechanism as a real world example. The RPI-X mechanism is a price cap adopted an annual inflation rate and a target productivity change factor"X", which will be reset every 3-5 years to reflect the current realized cost of service. Under the observation, firms under this regulation made their greatest cost reduction efforts in the earlier period and reduce the effort as the review approached.

Dilemma raised, solutions must be offered. Usually, there are two ways out. First, rely on the law. Because even without commitment , firm have the protection of law. So it can partly increase the confidence and stability of investments. Second approach, which is kind of meaningless, is abandon the incentive regulation, just use the rate of return regulation.

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reference:
  Paul L. Joskow, Regulation of Natural Monopolies
For more information:
1. Laffont and Tirole,(1993), A theory of Incentive in Regulation and procurement
2. Laffont and Tirole, Competition in Telecommunications

Friday, December 3, 2010

Suprise Today

Today when I went downstairs, I recieved a package from amazon. When I opened it, wow....THE BRO CODE AND PLAY BOOK by Barney Stinson. Phil, you know me so well. This birthday present is sooo cool, out of expectation and totally a keeper.

Anyone who is a fan of HIMYM as me would totally enjoy reading those two collections. I plan to quote some of my favorite articles tonight. Though I am not a bro, I feel like such a dude now..LOL
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One of the code told about the age difference of male and female. here is the page.







According to Bro's code:

The age difference of male and female follows this formula:

X<= Y/2 +7
X: chick's age
Y: Bro's age



The max age of women available is 7, when the boy was just born. 

As time pasted by, your last chance to have a girl at least at your same age is when you are 14.  Ever since then, all the women suitable for you would be younger than you.


If you are 100, the maximum age of woman would be 57. Say the max of longevity is100, then women above 57 years old is permanently out of market.


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To Bro Lansey,
Article 96:  Bros shall go camping once a year, or at least attempt to start a fire.
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