Sub-channel Assignment, Power Allocation and User Scheduling for Non-Orthogonal Multiple Access Networks

In this paper, we study the resource allocation and user scheduling problem for a downlink nonorthogonal multiple access network where the base station allocates spectrum and power resources to a set of users. We aim to jointly optimize the sub-channel assignment and power allocation to maximize the weighted total sum-rate while taking into account user fairness. We formulate the sub-channel allocation problem as equivalent to a many-to-many two-sided user-subchannel matching game in which the set of users and sub-channels are considered as two sets of players pursuing their own interests. We then propose a matching algorithm which converges to a two-side exchange stable matching after a limited number of iterations. A joint solution is thus provided to solve the sub-channel assignment and power allocation problems iteratively. Simulation results show that the proposed algorithm greatly outperforms the orthogonal multiple access scheme and a previous non-orthogonal multiple access scheme.Comment: Accepted as a regular paper by IEEE Transactions on Wireless Communication

Safety Net Design and Systemic Risk: New Empirical Evidence

Recent econometric evidence has noticeably changed views on the desirability and the appropriate design of explicit Deposit Insurance Schemes (DIS). The purpose of this paper is to take a second look at the data. After surveying recent empirical work and providing a theoretical framework, we argue that existing studies may suffer from a selection bias. Building on a new database on explicit deposit insurance compiled by the author, we perform a variety of semi-parametric and parametric tests to see whether and how explicit deposit insurance (de)stabilizes banking systems. We find that the evidence indeed suggests that a selection bias is present. Controlling for this bias leads to a reassessment of recent studies. In particular, making deposit insurance explicit has a rather moderate and, if any, stabilizing effect on the probability of experiencing a systemic crisis

Policies for mixed communities: faith-based displacement activity?

The belief that it is fairer if communities are ``mixed'' can be traced at least to the late nineteenth century and the founders of the Garden City Movement. The idea is now firmly established in Organization for Economic Cooperation and Development (OECD) and national policies. This article reviews the evidence and argues that this is essentially a faith-based policy because there is scant real evidence that making communities more mixed makes the life chances of the poor any better. There is overwhelming evidence that the attributes that make neighborhoods attractive are capitalized into house prices/rents. The result is that poor people cannot afford to buy into nicer neighborhoods, which anyway have amenities of no value to them. Moreover, ``specialized neighborhoods'' are an important element in agglomeration economies and seem to be welfare enhancing. Thus, policies for mixed neighborhoods treat the symptoms rather than the causes of poverty. Efforts to improve social equity would be more effectively directed toward people themselves rather than moving people around to mix neighborhoods

The impact of trade promotion services on Canadian exporter performance.

We evaluate the impact of the export promotion program delivered by the Canadian Trade Commissioner Service on various dimensions of export performance. Over the 1999-2006 time period we study, Canadian firms successfully diversified their exports to destinations beyond the United States and smaller firms increased their share of total exports. Both of these achievements are explicit aims of the program, but in order to make causal inferences we rely on various identifying assumptions from the treatment effects literature. The results indicate very robustly that the program had an effect at the intensive margin, boosting the average level of exports to given product-destination markets. Effects at the extensive margins of trade, increasing the number of export destinations or number of products exported, are smaller and more sensitive to the identification assumption. This finding differs from previous studies for several Latin American countries where extensive margin effects were most robust. One reason is that the Canadian program was most effective for larger firms and for firms already active on several export markets.

The impact of trade promotion services on Canadian exporter performance

We evaluate the impact of the programs delivered by the Canadian Trade Commissioner Service (TCS) on export performance by Canadian firms. We draw on a unique set of microdata created by linking three separate firm-level databases: Statistics Canada’s Exporter Register and its Business Register, which provide information on export activity and firm characteristics, and the TCS client management database maintained by Foreign Affairs and International Trade Canada, which contains details on trade promotion services provided to Canadian firms. We apply the treatment effects analytical framework to isolate the effects of public sector trade promotion. We find that TCS programs have a consistent and positive impact on Canadian exporter performance. Exporters that access TCS services export, on average, 17.9 percent more than comparable exporters that do not. Furthermore, we also find that TCS assistance benefits exporters in terms of product and market diversification.Export Promotion, Heterogeneous Firms, Canada

The impact of trade promotion services on Canadian exporter performance.

We evaluate the impact of the programs delivered by the Canadian Trade Commissioner Service (TCS) on export performance by Canadian firms. We draw on a unique set of microdata created by linking three separate firm-level databases: Statistics Canada’s Exporter Register and its Business Register, which provide information on export activity and firm characteristics, and the TCS client management database maintained by Foreign Affairs and International Trade Canada, which contains details on trade promotion services provided to Canadian firms. We apply the treatment effects analytical framework to isolate the effects of public sector trade promotion. We find that TCS programs have a consistent and positive impact on Canadian exporter performance. Exporters that access TCS services export, on average, 17.9 percent more than comparable exporters that do not. Furthermore, we also find that TCS assistance benefits exporters in terms of product and market diversification.