Insights into the Design of Congestion Control Protocols for Multi-Hop Wireless Mesh Networks

The widespread deployment of multi-hop wireless mesh networks will depend on the performance seen by the user. Unfortunately, the most predominant transport protocol, TCP, performs poorly over such networks, even leading to starvation in some topologies. In this work, we characterize the root causes of starvation in 802.11 scheduled multi-hop wireless networks via simulations. We analyze the performance of three categories of transport protocols. (1) end-to-end protocols that require implicit feedback (TCP SACK), (2) Explicit feedback based protocols (XCP and VCP) and (3) Open-loop protocol (UDP). We ask and answer the following questions in relation to these protocols: (a) Why does starvation occur in different topologies? Is it intrinsic to TCP or, in general, to feedback-based protocols? or does it also occur in the case of open-loop transfers such as CBR over UDP? (a) What is the role of application behavior on transport layer performance in multi-hop wireless mesh networks? (b) Is sharing congestion in the wireless neighborhood essential for avoiding starvation? (c) For explicit feedback based transport protocols, such as XCP and VCP, what performance can be expected when their capacity estimate is inaccurate? Based on the insights derived from the above analysis, we design a rate-based protocol called VRate that uses the two ECN bits for conveying load feedback information. VRate achieves near optimal rates when configured with the correct capacity estimate

Provincial Finance Commission: Options for Fiscal Transfers

The Provincial Finance Commissions were constituted in all four provinces of Pakistan in 2001. The Commissions were asked to formulate a formula for the distribution of resources among the districts in their respective province to ensure smooth functioning of the local governments and to minimise the poverty and income inequalities among the districts. This paper analyse to what extent the existing development transfers are based on the existing level of deprivation in the districts by looking at the Rank Correlation between them. This paper also runs different simulations to suggest different options for the provincial governments to improve the distribution formulas.

Determinants of Total Factor Productivity in Pakistan

The role of productivity in accelerating the pace of economic growth is well recognized in economic literature and this paper shows that Pakistan’s case is no exception. The purpose of the paper was also to see the effect of government fiscal policy, monetary policy and other economic measures on TFP. It shows that these policies affect TFP through human capital endowments of employed labor force, providing better physical infrastructure and other facilitation to incorporate technology in the production process. Using data of the Pakistan economy from 1973 to 2006 both at aggregate and dis-aggregated levels i.e. Agriculture, Manufacturing, Construction, Electricity and Gas, and Other Sectors, the paper has tried to explain TFP for seven sub-periods equally divided into five years.Productivity; Growth; Human Capital; employment; TFP;

The Burden of Stabilisation on Provinces and its Implications for the Social Sectors

An agenda of economic reform encompassing a broad range of structural adjustment policies (SAP) is underway in Pakistan since 1987-88. These policies have an adverse impact on the pace of economic growth and created more poverty and inequality in the country [see Bengali and Ahmed (2002); Kemal (2003)]. These studies argues that during the last fifteen years each government is trying to stabilise the economy even at the cost of economic growth and delivery of social services. The negative impact of stabilisation policies on economic growth of the country is reflected in the decline of GDP growth from an average annual growth of 4.6 percent during 1990s as compared to 6.5 percent during 1980s. Similarly, negligence of social services delivery is reflected in the recent UNDP Report (2003), which, show that the ranking of Pakistan has slipped from 136 to 141 along with the decline in many other social sector statistics. The top government officials now also recognise these facts and the relapse of growth oriented policy can be heard more often. Trend in public finance statistics of the country clearly indicate that one of the important victim of stabilisation policies are the expenditures of provincial governments. In last several years the significant portion of onus of containment of fiscal deficit has been shifted towards the provincial governments. The onus of containment of fiscal deficit by all four provincial governments during the last decade has increased from 18 percent to 50 percent, which has devastating impact on the service provision and poverty reduction.

Political Economy of Fiscal Reforms in the 1990s

Throughout the decade of the 1990s, major emphasis in Pakistan remained on fiscal reform as a part of the reform programmes undertaken by the various governments of Pakistan. Fiscal reform assumes significance considering the high budget deficits that Pakistan has been experiencing. These have added to Pakistan’s total debt burden in general and external debt in particular. Increase in the burden of debt adds to debt-servicing expenditure which further feeds back into the issue of high fiscal deficit. Debt-servicing increased to almost 47 percent1 by the middle of the decade of 1990s and comprised 8.3 percent of the GDP, up from less than 1 percent mid-1960s. Pakistan’s external debt at over $32 billion2 in 1998 was 41 percent of its GNP which was amongst the highest in the South Asian region with India’s at 20 percent of GNP in the same year and Sri Lanka’s also at 41 percent3 of its GNP. In this paper, we attempt to explore the rationale behind the emphases on the improvement in both the deficit-to-GDP and the tax-to-GDP ratios that have remained the cornerstones of Pakistan’s fiscal reform effort in the decade of the 1990s. Section 2 is a discussion of the extent of successes and failures of the fiscal reform effort thus far and explores the relationship between tax generation and budget deficit. Section 3 discusses the impact of expenditures on budget deficit. Section 4 shows the rise in dependence on external sources of financing. Section 5 gives the conclusions.

The Determinants of Foreign Direct Investment in Pakistan: an Empirical Investigation

The changing modes of international transactions and the cross-border mobilisation of factor resources, in pursuance of transnational production, constitute new dimensions for sustained economic growth. Foreign Direct Investment (an influential element of this process) is defined as the source of acquisition of managerial control by a business enterprise of a foreign country over a business activity in a host country [Graham (1982)]. The changing perceptions and more attractive policies of the host developing nations have changed the destinations of FDI flows from industrially developed countries to high growth developing centres. FDI stock held by developing countries has risen from $132.95 billion in 1980 to$ 1438.48 billion in 1999. Their share in inward stock has reached to 30.14 percent in 1999 as against 26.2 percent in 1980. FDI inflows during this period were raised from $4.42 billion to$ 208.0 billion, at an annual growth rate of 22.5 percent while GDP growth rate for that period was 3.9 percent. FDI brings the most needed capital fund, advanced production technique, snobbish managerial skills, advertising and marketing expertise, global links and the controversial phenomenon of “transfer pricing”.1 Pakistan, the world’s 7th most populated country with 140 million people, a relatively high growth rate of GDP (averaging around 6 percent), with a significant stock of natural resources and a variety of investment provisions has remained unattractive for FDI inflows.

Estimation of the Black Economy of Pakistan through the Monetary Approach

In the recent years the “black economy” has held immense attraction for academics as well as policy-makers. This is because the presence of the black economy is responsible for distortions in the official estimates of macro-economic variables like income generation, employment, rate of inflation, etc., and thus the possible effect on the economic policies cannot be ascertained properly. It, therefore, becomes imperative to investigate this area of research. Researchers have defined the underground economy in alternative ways. The underground economy defined by varied names like black, shadow, hidden, informal, clandestine, second, parallel economy has been divided in four categories for the use of a standard basis of classification.

Stabilisation Policy vs. Growth-oriented Policy: Implication for the Pakistan Economy

Pakistan has initiated a comprehensive reforms efforts aiming at tracking the economy on a higher and sustainable economic growth, reduce level of poverty, reducing unemployment, raising their level of standard of living. These objective were to be achieved through a programme that would build on the macro-economic stability which encompasses structural reforms, trade liberalisation, privatisation, fiscal reforms and financial sector. This paper makes one of the early attempt to analyse the Pakistan stabilisation experiences. In Pakistan the stabilisation programme was started in 1988-89. In this paper we mainly examine the fiscal and monetary policy package since 1988 when the Pakistan committed to a set of conditionalities under the Structural Adjustment Programme of the IMF. The fundamental question that has risen was the relative efficacy of stabilisation oriented versus growth oriented policies on development and welfare. Admittedly, stabilisation and growth are not mutually exclusive and any policy package has to incorporate both the elements. However, the manner in which the policy has been implemented in Pakistan has tended to pursue stabilisation at the expense of growth.