39-343 transaction costs, 181 history of, 334-347 interexchange carriers (IXCs), 154 market-based pricing, 369-372 intermediary, 17 network neutrality debate, 343-347 backbone as, 411n4 rationales for, 348-356 role in reducing transaction costs, 17, 18f managed competition, 354-356 internal access, 33 natural monopoly, 348-351 international trade, business/social networks role in, network economic effects, 351-352 vertical exclusion, 352-354 See also last-mile Internet providers backbone providers, 409-411 last-mile providers basic architecture of, 410f interconnection access and, 266-268 bursty traffic on, 363-364 platform access and, 330 cable modem termination system, 410 transaction costs, 422 complementary services, 112 unbundled access and, 274-275 flat-fee pricing, 407-408 law of unintended consequences, 3, 39 information storage using tree structure, 26 layered model, 379n12 last-mile providers, 409-411 Le Chatelier principle, 74n16, 160n12 measurement of services on, 50 Lee, William E., 349n27 middle-mile providers, 409-411 Lemley, Mark, 351 as open network, 34 Lessig, Lawrence, 345, 351, 373, 379n12, 386n19, physical network of, 15 399-400, 400n43, 401, 401n45, 402, 406, routers, 410 425n20 servers, 410 Level 3, 15 sources of congestion on, 409-412 Lexis, 389 standardization and, 364 Liebman, Lance, 394n31 usage-sensitive pricing, 407. See also broadband Liebowitz, Stan J., 113n25, 139n23, 140n24 networks and Internet regulation lighthouse financing, 407, 419-420 Internet Service Providers (ISPs), 15, 154, 344 Line Sharing Order, 350, 353, 369 multiple ISP access, 344-345 links, 19 Internet telephony. See voice over Internet protocol capacity of, 22, 22f Interstate Commerce Commission (ICC), 234n3 geographic distance between, 23, 23f Mann-Elkins Act, 234 types of, 20 trackage rights, 198 Lipartito, Kenneth, 244n14 intramodal natural monopoly, 348 local exchange carriers (LECs), 155-156, 266-268 takings and, 278-279 Jacobs, Michael, 312n93 local loop, as unbundled network element, 29, 132 local measured 