Author Page for Hal J. Singer

1.

Unintended Consequences of Net Neutrality Regulation

Journal on Telecommunications and High Technology Law, 2007

Number of pages: 33 Posted: 03 Nov 2006

Hal J. Singer and Robert E. Litan

Econ One and Council on Foreign Relations (CFR) - Council on Foreign Relations- Washington D.C.

Downloads 1,876 (10,582)

Abstract:

2.

A General Framework for Competitive Analysis in Wireless Telecommunications

Hastings Law Journal, Vol. 50, No. 6, pp. 1639-1672, August 1999

Number of pages: 36 Posted: 26 Jan 2001

J. Gregory Sidak, Hal J. Singer and David Teece

Criterion Economics, Inc., Econ One and Institute for Business Innovation

Downloads 1,852 (10,789)

Citation 1

Abstract:

3.

Open Access to Broadband Networks: A Case Study of the Aol/Time Warner Merger

UC Berkeley Public Law Research Paper No. 54

Number of pages: 46 Posted: 07 May 2001

Daniel L. Rubinfeld and Hal J. Singer

University of California at Berkeley - School of Law and Econ One

Downloads 1,703 (12,347)

Abstract:

4.

The Empirical Case Against Asymmetric Regulation of Broadband Internet Access

Berkeley Technology Law Journal, Vol. 17, No. 3, pp. 953-987, Summer 2002

Number of pages: 35 Posted: 14 Mar 2003

J. Gregory Sidak, Robert W. Crandall and Hal J. Singer

Criterion Economics, Inc., Brookings Institution and Econ One

Downloads 1,624 (13,314)

Citation 9

Abstract:

5.

An Antitrust Analysis of Google's Proposed Acquisition of DoubleClick

AEI-Brookings Joint Center Related Publication No. 07-24

Number of pages: 44 Posted: 27 Sep 2007 Last Revised: 25 Oct 2012

Robert W. Hahn and Hal J. Singer

Technology Policy Institute and Econ One

Downloads 1,617 (13,387)

Citation 2

Abstract:

6.

Net Neutrality Regulation: The Economic Evidence

Number of pages: 32 Posted: 10 Apr 2010 Last Revised: 21 Apr 2013

Independent, University of Warwick - Warwick Business School, Brookings Institution, The American Consumer Institute, ESC Company, NERA Economic Consulting, George Washington University - Regulatory Studies Center, Independent, Carnegie Mellon University - School of Computer Science, University of Pennsylvania - Wharton School, Technology Policy Institute, National Economic Research Associates Inc. (NERA) (Deceased), Francisco Marroquin University, Council on Foreign Relations (CFR) - Council on Foreign Relations- Washington D.C., University of Virginia School of Law, Econ One, Chapman University - Economic Science Institute, Marsh & McLennan Companies - Cambridge Office, Advanced Analytical Consulting Group, Inc., London Business School and Kansas State University - Department of Economics

Downloads 1,496 (15,146)

Citation 4

Abstract:

7.

The Economics of 'Wireless Net Neutrality'

AEI-Brookings Joint Center Working Paper No. RP07-10

Number of pages: 53 Posted: 28 Apr 2007

Robert W. Hahn, Robert E. Litan and Hal J. Singer

Technology Policy Institute, Council on Foreign Relations (CFR) - Council on Foreign Relations- Washington D.C. and Econ One

Downloads 1,465 (15,680)

Citation 12

Abstract:

8.

Competition in Broadband Provision and Its Implications for Regulatory Policy

Number of pages: 228 Posted: 17 Dec 2003 Last Revised: 25 Feb 2010

Dan Maldoom, Richard Marsden, J. Gregory Sidak and Hal J. Singer

DotEcon, DotEcon, Criterion Economics, Inc. and Econ One

Downloads 1,229 (20,454)

Citation 9

Abstract:

9.

Cable Modems and DSL: Broadband Internet Access for Residential Customers

American Economic Association Papers & Proceedings, Vol. 91, No. 2, pp. 302-307, 2001

Number of pages: 6 Posted: 09 Jan 2002 Last Revised: 22 Dec 2013

Jerry A. Hausman, J. Gregory Sidak and Hal J. Singer

Massachusetts Institute of Technology (MIT) - Department of Economics, Criterion Economics, Inc. and Econ One

Downloads 1,220 (20,678)

Citation 9

Abstract:

10.

Residential Demand for Broadband Telecommunications and Consumer Access to Unaffiliated Internet Content Providers

Yale Journal on Regulation, Vol. 18, No. 1, pp. 129-173, 2001

Number of pages: 45 Posted: 30 Apr 2001

J. Gregory Sidak, Hal J. Singer and Jerry A. Hausman

Criterion Economics, Inc., Econ One and Massachusetts Institute of Technology (MIT) - Department of Economics

Downloads 861 (34,200)

Abstract:

11.

How Often Do 'Conflicts of Interests' in the Investment Banking Industry Arise During Hostile Takeovers?

Number of pages: 32 Posted: 28 Feb 2004

Charles W. Calomiris and Hal J. Singer

Columbia University - Columbia Business School and Econ One

Downloads 828 (36,067)

Citation 8

Abstract:

12.

Does Video Delivered over a Telephone Network Require a Cable Franchise?

Federal Communications Law Journal, Vol. 59, No. 2, pp. 251-294, March 2007

Number of pages: 44 Posted: 26 Sep 2006 Last Revised: 25 Feb 2010

Robert W. Crandall, J. Gregory Sidak and Hal J. Singer

Brookings Institution, Criterion Economics, Inc. and Econ One

Downloads 778 (39,273)

Abstract:

13.

Evaluating Market Power with Two-Sided Demand and Preemptive Offers to Dissipate Monopoly Rent: Lessons for High-Technology Industries from the Antitrust Division's Approval of the XM-Sirius Satellite Radio Merger

Downloads 733 ( 42,627)

Citation 1

2

Evaluating Market Power with Two-Sided Demand and Preemptive Offers to Dissipate Monopoly Rent: Lessons for High-Technology Industries from the Antitrust Division's Approval of the XM-Sirius Satellite Radio Merger

Journal of Competition Law and Economics, Vol. 4, No. 3, pp. 697-751, 2008

Number of pages: 55 Posted: 31 Jan 2008 Last Revised: 02 Nov 2009

J. Gregory Sidak and Hal J. Singer

Criterion Economics, Inc. and Econ One

Downloads 733 (42,026)

Citation 1

Abstract:

Evaluating Market Power with Two-Sided Demand and Preemptive Offers to Dissipate Monopoly Rent: Lessons for High-Technology Industries from the Antitrust Division's Approval of the XM-Sirius Satellite Radio Merger

Journal of Competition Law and Economics, Vol. 4, Issue 3, pp. 697-751, 2008

Posted: 08 Oct 2008

J. Gregory Sidak and Hal J. Singer

Criterion Economics, Inc. and Econ One

Abstract:

14.

Why the iPhone Won't Last Forever and What the Government Should Do to Promote its Successor

Number of pages: 30 Posted: 23 Sep 2009 Last Revised: 11 Oct 2009

Robert W. Hahn and Hal J. Singer

Technology Policy Institute and Econ One

Downloads 720 (43,643)

Citation 1

Abstract:

15.

Assessing Bias in Patent Infringement Cases: A Review of International Trade Commission Decisions

AEI-Brookings Joint Center Working Paper No. RP07-03, Harvard Journal of Law and Technology, Vol. 21, No. 2, Spring 2008

Number of pages: 54 Posted: 10 Mar 2009 Last Revised: 05 Dec 2014

Robert W. Hahn and Hal J. Singer

Technology Policy Institute and Econ One

Downloads 655 (49,465)

Abstract:

16.

Assessing Competition in U.S. Wireless Markets: Review of the FCC’s Competition Reports

Number of pages: 55 Posted: 07 Jul 2011 Last Revised: 12 Sep 2014

Gerald R. Faulhaber, Robert W. Hahn and Hal J. Singer

University of Pennsylvania - Wharton School, Technology Policy Institute and Econ One

Downloads 599 (55,592)

Citation 8

Abstract:

17.

Bundles in the Pharmaceutical Industry: A Case Study of Pediatric Vaccines

Number of pages: 62 Posted: 11 Aug 2011 Last Revised: 01 Oct 2011

Kevin W. Caves and Hal J. Singer

Infotech Consulting and Econ One

Downloads 459 (77,373)

Citation 1

Abstract:

18.

Are Google’s Search Results Unfair or Deceptive Under Section 5 of the FTC Act?

Number of pages: 19 Posted: 08 May 2012

Robert E. Litan and Hal J. Singer

Council on Foreign Relations (CFR) - Council on Foreign Relations- Washington D.C. and Econ One

Downloads 452 (78,793)

Citation 2

Abstract:

19.

When the Econometrician Shrugged: Identifying and Plugging Gaps in the Consumer Welfare Standard

George Mason Law Review, 2018

Number of pages: 28 Posted: 23 Jul 2018

Kevin W. Caves and Hal J. Singer

Infotech Consulting and Econ One

Downloads 397 (91,647)

Citation 2

Abstract:

20.

Letter to Fcc Chairman Powell Concerning Auction 35

Number of pages: 3 Posted: 06 Dec 2002

Peter Cramton, Robert W. Crandall, Robert W. Hahn, Robert G. Harris, Jerry A. Hausman, Thomas W. Hazlett, Douglas Lichtman, Paul W. MacAvoy, Paul R. Milgrom, J. Gregory Sidak, Richard Schmalensee, Hal J. Singer, Vernon L. Smith, William E. Taylor and David Teece

University of Maryland - Department of Economics, Brookings Institution, Technology Policy Institute, University of California, Berkeley - Business & Public Policy Group, Massachusetts Institute of Technology (MIT) - Department of Economics, Clemson University, University of California, Los Angeles (UCLA) - School of Law, Yale School of Management (Deceased), Stanford University, Criterion Economics, Inc., Massachusetts Institute of Technology (MIT) - Sloan School of Management, Econ One, Chapman University - Economic Science Institute, Marsh & McLennan Companies - Cambridge Office and Institute for Business Innovation

Downloads 351 (105,456)

Abstract:

21.

Net Neutrality: A Radical Form of Non-Discrimination

Regulation, Vol. 30, No. 2, pp. 36-41, Summer 2007

Number of pages: 6 Posted: 10 Mar 2009 Last Revised: 21 Apr 2013

Hal J. Singer

Econ One

Downloads 349 (106,122)

Abstract:

22.

Uberregulation Without Economics: The World Trade Organization's Decision in the U.S.-Mexico Arbitration on Telecommunications Services

Federal Communications Law Journal, Vol. 57, No. 1, pp. 1-48, December 2004

Number of pages: 49 Posted: 17 Aug 2004 Last Revised: 02 Nov 2009

J. Gregory Sidak and Hal J. Singer

Criterion Economics, Inc. and Econ One

Downloads 329 (113,347)

Citation 4

Abstract:

23.

Do Unbundling Policies Discourage Clec Facilities-Based Investment?

Number of pages: 17 Posted: 21 Apr 2003

Robert W. Crandall, Allan T. Ingraham and Hal J. Singer

Brookings Institution, Economists Incorporated and Econ One

Downloads 327 (114,147)

Citation 21

Abstract:

24.

The Benefits of a Secondary Market for Life Insurance Policies

Real Property, Probate and Trusts Journal, Vol. 38, 2003

Number of pages: 38 Posted: 22 Apr 2003 Last Revised: 26 Nov 2011

Neil A. Doherty and Hal J. Singer

University of Pennsylvania - Insurance & Risk Management Department and Econ One

Downloads 322 (116,056)

Citation 5

Abstract:

25.

Should the FCC Depart from More than a Decade of Market-Oriented Spectrum Policy? Reply to Skrzypacz and Wilson

Number of pages: 34 Posted: 18 Jun 2007

Gerald R. Faulhaber, Robert W. Hahn and Hal J. Singer

University of Pennsylvania - Wharton School, Technology Policy Institute and Econ One

Downloads 321 (116,419)

Citation 1

Abstract:

26.

Class Certification in Antitrust Cases: An Economic Framework

George Mason Law Review, Forthcoming

Number of pages: 27 Posted: 15 Mar 2010

Hal J. Singer and Robert B. Kulick

Econ One and NERA Economic Consulting

Downloads 297 (126,483)

Abstract:

27.

Inter-City Competition for Retail Trade: Can Tax Increment Financing Generate Incremental Tax Receipts?

Number of pages: 15 Posted: 28 Jul 2005

Allan T. Ingraham, Hal J. Singer and Thomas G. Thibodeau

Economists Incorporated, Econ One and University of Colorado at Boulder - Leeds School of Business

Downloads 272 (138,617)

Citation 2

Abstract:

28.

Are Vertically Integrated Dsl Providers Squeezing Unaffiliated Isps (and Should We Care)?

Number of pages: 24 Posted: 02 May 2005

Robert W. Crandall and Hal J. Singer

Brookings Institution and Econ One

Downloads 272 (138,617)

Citation 1

Abstract:

29.

Foxes in the Henhouse: FCC Regulation through Merger Review

Milken Institute Review, Vol. 10, No. 1, pp. 46-54, First Quarter 2008

Number of pages: 10 Posted: 06 Feb 2008 Last Revised: 05 Jan 2014

J. Gregory Sidak and Hal J. Singer

Criterion Economics, Inc. and Econ One

Downloads 265 (142,386)

Abstract:

30.

Irrational Expectations: Can a Regulator Credibly Commit to Removing an Unbundling Obligation?

AEI-Brookings Related Publication No. 07-28

Number of pages: 34 Posted: 10 Mar 2009 Last Revised: 14 Apr 2009

Jeffrey A. Eisenach and Hal J. Singer

NERA Economic Consulting and Econ One

Downloads 254 (148,558)

Citation 2

Abstract:

31.

Does Clustering by Incumbent Cable Msos Deter Entry by Overbuilders?

Number of pages: 15 Posted: 05 May 2003

Hal J. Singer

Econ One

Downloads 242 (155,718)

Citation 4

Abstract:

32.

The Economic Impact of Eliminating Preemption of State Consumer Protection Laws

The University of Pennsylvania Journal of Business Law, Forthcoming

Number of pages: 34 Posted: 22 Sep 2009 Last Revised: 21 Jan 2020

Joseph R. Mason, Robert B. Kulick and Hal J. Singer

Louisiana State University - Ourso School of Business, NERA Economic Consulting and Econ One

Downloads 241 (156,354)

Abstract:

33.

Vertical Foreclosure in Video Programming Markets: Implications for Cable Operators

Review of Network Economics, Vol. 6, pp. 348-371, 2007

Number of pages: 24 Posted: 01 Aug 2007 Last Revised: 02 Nov 2009

Hal J. Singer and J. Gregory Sidak

Econ One and Criterion Economics, Inc.

Downloads 224 (167,756)

Abstract:

34.

Antitrust Out of Focus: The FTC's Myopic Pursuit of 1-800 Contacts' Trademark Settlements

The Antitrust Source (April 2019)

Number of pages: 8 Posted: 05 Jan 2019 Last Revised: 25 Apr 2019

Geoffrey A. Manne, Hal J. Singer and Joshua D. Wright

International Center for Law & Economics (ICLE), Econ One and George Mason University - Antonin Scalia Law School, Faculty

Downloads 180 (204,924)

Abstract:

35.

Is the U.S. Government's Internet Policy Broken?: A Review of Captive Audience by Susan Crawford

Georgetown McDonough School of Business Research Paper

Number of pages: 24 Posted: 26 Jan 2013

Robert W. Hahn and Hal J. Singer

Technology Policy Institute and Econ One

Downloads 170 (215,325)

Citation 2

Abstract:

36.

The Static and Dynamic Inefficiency of Abandoning Unrestricted Auctions for Spectrum: A Critique of Professor Wilkie's Analysis of the M2Z Proposal

Number of pages: 32 Posted: 18 Aug 2008 Last Revised: 25 Dec 2013

Robert W. Hahn, Allan T. Ingraham, J. Gregory Sidak and Hal J. Singer

Technology Policy Institute, Economists Incorporated, Criterion Economics, Inc. and Econ One

Downloads 164 (221,980)

Abstract:

37.

Letter to Chairman Wheeler: Economic Evidence on Competition in Communications Markets and Implications for Key Policy Issues

Number of pages: 7 Posted: 13 Dec 2013

Robert D. Atkinson, Kevin W. Caves, Robert W. Crandall, Wayne Crews, Everett Ehrlich, Jeffrey A. Eisenach, Gerald R. Faulhaber, Robert W. Hahn, Kevin A. Hassett, Steve Pociask, Hal J. Singer, Timothy J. Tardiff, Leonard Waverman and Dennis Weisman

Information Technology and Innovation Foundation, Infotech Consulting, Brookings Institution, Competitive Enterprise Institute (CEI), ESC Company, NERA Economic Consulting, University of Pennsylvania - Wharton School, Technology Policy Institute, American Enterprise Institute (AEI), The American Consumer Institute, Econ One, Advanced Analytical Consulting Group, Inc., Berkeley Research Group,LLC and Kansas State University - Department of Economics

Downloads 162 (224,244)

Citation 1

Abstract:

38.

The Competitive Effects of a Cable Television Operator's Refusal to Carry Dsl Advertising

Journal of Competition Law and Economics, Vol. 2, No. 2, pp. 301-331, 2006

Number of pages: 31 Posted: 08 Sep 2006

Hal J. Singer

Econ One

Downloads 160 (226,599)

Abstract:

39.

Assessing DOJ’s Proposed Remedy in Sprint/T-Mobile: Can Ex Ante Competitive Conditions in Wireless Markets Be Restored?

NET Institute Working Paper No. 19-14, NYU Stern School of Business

Number of pages: 14 Posted: 21 Oct 2019

Nicholas Economides, John E. Kwoka Jr., Thomas Philippon, Robert Seamans, Hal J. Singer, Marshall Steinbaum and Lawrence J. White

New York University - Leonard N. Stern School of Business - Department of Economics, Northeastern University - Department of Economics, New York University (NYU) - Department of Finance, New York University (NYU) - Leonard N. Stern School of Business, Econ One, University of Utah Department of Economics and New York University (NYU) - Leonard N. Stern School of Business, Department of EconomicsStern School of Business, New York University

Downloads 156 (231,516)

Citation 1

Abstract:

40.

Observations on the Current Canadian Ownership Debate in Telecommunications

Criterion Working Paper No. 03-02

Number of pages: 23 Posted: 21 Apr 2003

Robert W. Crandall and Hal J. Singer

Brookings Institution and Econ One

Downloads 145 (245,887)

Abstract:

41.

An Economic Assessment of the Weight-Based Cafe Standard Proposed by the National Highway Traffic Safety Administration

Number of pages: 35 Posted: 07 May 2004

Robert W. Crandall, Allan T. Ingraham and Hal J. Singer

Brookings Institution, Economists Incorporated and Econ One

Downloads 144 (247,284)

Citation 1

Abstract:

42.

The Consumer Benefits of Efficient Mobile-Number-Portability Administration

Number of pages: 22 Posted: 19 Feb 2014

Hal J. Singer

Econ One

Downloads 133 (263,164)

Abstract:

43.

The Impact of Incumbent Bidding in Set-Aside Auctions: An Analysis of Prices in the Closed and Open Segments of Fcc Auction 35

Criterion Working Paper No. 02-07

Number of pages: 43 Posted: 22 Apr 2003

Peter Cramton, Allan T. Ingraham and Hal J. Singer

University of Maryland - Department of Economics, Economists Incorporated and Econ One

Downloads 117 (289,318)

Citation 3

Abstract:

44.

Economists’ Tunney Act Reply Comments on the DOJ’s Proposed Remedy in the Sprint/T-Mobile Merger Proceeding

NET Institute Working Paper No. 20-02, 2020, NYU Stern School of Business

Number of pages: 468 Posted: 26 Jan 2020

Nicholas Economides, John E. Kwoka Jr., Thomas Philippon, Robert Seamans, Hal J. Singer, Marshall Steinbaum and Lawrence J. White

New York University - Leonard N. Stern School of Business - Department of Economics, Northeastern University - Department of Economics, New York University (NYU) - Department of Finance, New York University (NYU) - Leonard N. Stern School of Business, Econ One, University of Utah Department of Economics and New York University (NYU) - Leonard N. Stern School of Business, Department of EconomicsStern School of Business, New York University

Downloads 89 (346,861)

Abstract:

45.

How Can Regulators Set Nonarbitrary Interim Rates? The Case of Local Loop Unbundling in Ireland

Journal of Network Industries, Vol. 3, pp. 273-295, 2002

Number of pages: 23 Posted: 22 Apr 2003

J. Gregory Sidak and Hal J. Singer

Criterion Economics, Inc. and Econ One

Downloads 77 (378,115)

Abstract:

46.

Interim Pricing of Local Loop Unbundling in Ireland: Epilogue

Journal of Network Industries, Vol. 4, No. 2, pp. 119-135, 2003

Number of pages: 18 Posted: 23 Feb 2007

J. Gregory Sidak and Hal J. Singer

Criterion Economics, Inc. and Econ One

Downloads 62 (424,647)

Abstract:

47.

Comments on the DOJ/FTC Draft Vertical Merger Guidelines

NET Institute Working Paper No. #20-04, 2020, NYU Stern School of Business

Number of pages: 10 Posted: 20 Feb 2020

Nicholas Economides, John E. Kwoka Jr., Thomas Philippon, Hal J. Singer and Lawrence J. White

New York University - Leonard N. Stern School of Business - Department of Economics, Northeastern University - Department of Economics, New York University (NYU) - Department of Finance, Econ One and New York University (NYU) - Leonard N. Stern School of Business, Department of EconomicsStern School of Business, New York University

Downloads 60 (431,621)

Citation 2

Abstract:

48.

State of New York v. Deutsche Telecom AG. Brief of Amici Curiae Nicholas Economides, John Kwoka, Thomas Philippon, Robert Seamans, Hal Singer, Marshall Steinbaum, and Lawrence J. White in Support of Plaintiffs

NET Institute Working Paper No. #20-01, NYU Stern School of Business

Number of pages: 20 Posted: 15 Jan 2020

Nicholas Economides, John E. Kwoka Jr., Thomas Philippon, Robert Seamans, Hal J. Singer, Marshall Steinbaum and Lawrence J. White

New York University - Leonard N. Stern School of Business - Department of Economics, Northeastern University - Department of Economics, New York University (NYU) - Department of Finance, New York University (NYU) - Leonard N. Stern School of Business, Econ One, University of Utah Department of Economics and New York University (NYU) - Leonard N. Stern School of Business, Department of EconomicsStern School of Business, New York University

Downloads 56 (446,108)

Abstract:

49.

Life Support for Unaffiliated Isps?

Regulation, Vol. 28, No. 3, pp. 46-52, Fall 2005

Number of pages: 7 Posted: 13 Oct 2005

Robert W. Crandall and Hal J. Singer

Brookings Institution and Econ One

Downloads 55 (449,746)

Abstract:

50.

The FCC's Incentive Auction: Getting Spectrum Policy Right

Progressive Policy Institute, Backgrounder, Sept. 2013

Number of pages: 12 Posted: 06 Sep 2013

David A. Balto and Hal J. Singer

Law Offices of David A. Balto PLLC and Econ One

Downloads 49 (472,953)

Abstract:

51.

Improving Public Safety Communications: An Analysis of Alternative Approaches

Number of pages: 43 Posted: 24 Oct 2011

Jeffrey A. Eisenach, Peter Cramton, Thomas S. Dombrowsky, Allan T. Ingraham and Hal J. Singer

NERA Economic Consulting, University of Maryland - Department of Economics, affiliation not provided to SSRN, Economists Incorporated and Econ One

Downloads 31 (558,097)

Abstract:

52.

The Economics of Wireless Net Neutrality

Journal of Competition Law and Economics, Vol. 3, Issue 3, pp. 399-451, 2007

Posted: 14 Jul 2008

Robert W. Hahn, Robert E. Litan and Hal J. Singer

Technology Policy Institute, Council on Foreign Relations (CFR) - Council on Foreign Relations- Washington D.C. and Econ One

Hal J. Singer

Econ One

Managing Director

52

Top 1,288

26,640

Top 9,443

61

75

Scholarly Papers (52)

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract: