Considering a Consumption Tax

A combination of electronic commerce and the Flat Tax could eliminate the IRS as we know it

Universal Health Care, American Pragmatism, and the Ethics of Health Policy: Questioning Political Efficacy

[Excerpt] “This article will explore the conceptual implications of applying ethical critique and analysis to health policy. This is not to imply any reductionist conception of health policy in which ethics is absent. As Deborah Stone and John W. Kingdon both note, policy is fraught with ethical implications, and value prioritization is a sine qua non for health policy. Nevertheless, I wish to suggest that there are some conceptually significant distinctions in thinking of the ethics of health policy as opposed to thinking separately about ethics and about health policy. Moreover, these distinctions themselves are of value, both in thinking about some of the most intractable problems of health policy, and in generating health policy that expressly presents its ethical bases, as opposed to masking the value assumptions and beliefs that underpin such policy.

The complexity of approximating the matching polynomial in the complex plane

We study the problem of approximating the value of the matching polynomial on graphs with edge parameter $\gamma$, where $\gamma$ takes arbitrary values in the complex plane. When $\gamma$ is a positive real, Jerrum and Sinclair showed that the problem admits an FPRAS on general graphs. For general complex values of $\gamma$, Patel and Regts, building on methods developed by Barvinok, showed that the problem admits an FPTAS on graphs of maximum degree $\Delta$ as long as $\gamma$ is not a negative real number less than or equal to $-1/(4(\Delta-1))$. Our first main result completes the picture for the approximability of the matching polynomial on bounded degree graphs. We show that for all $\Delta\geq 3$ and all real $\gamma$ less than $-1/(4(\Delta-1))$, the problem of approximating the value of the matching polynomial on graphs of maximum degree $\Delta$ with edge parameter $\gamma$ is #P-hard. We then explore whether the maximum degree parameter can be replaced by the connective constant. Sinclair et al. showed that for positive real $\gamma$ it is possible to approximate the value of the matching polynomial using a correlation decay algorithm on graphs with bounded connective constant (and potentially unbounded maximum degree). We first show that this result does not extend in general in the complex plane; in particular, the problem is #P-hard on graphs with bounded connective constant for a dense set of $\gamma$ values on the negative real axis. Nevertheless, we show that the result does extend for any complex value $\gamma$ that does not lie on the negative real axis. Our analysis accounts for complex values of $\gamma$ using geodesic distances in the complex plane in the metric defined by an appropriate density function

Foreign and domestic bank participation in emerging markets: lessons from Mexico and Argentina

It is generally agreed that strong domestic financial systems play an important role in attaining overall economic development and stabilization. The role played by foreign banks in achieving this goal, however, is still controversial. This article brings new evidence to the debate over foreign participation by examining the lending patterns of domestic and foreign banks in Argentina and Mexico during the 1990s. The authors conclude that foreign banks in both countries typically have stronger and less volatile loan growth than their domestic counterparts. The corollary to this finding, however, is that bank health—not ownership per se—is the critical element in the growth, volatility, and cyclicality of bank credit. Still, diversity of ownership is found to contribute to greater credit stability in times of financial system turmoil and weakness.Bank loans - Argentina ; Bank loans - Mexico ; Banks and banking, Foreign ; Argentina ; Mexico

Inapproximability of the independent set polynomial in the complex plane

We study the complexity of approximating the independent set polynomial $Z_G(\lambda)$ of a graph $G$ with maximum degree $\Delta$ when the activity $\lambda$ is a complex number. This problem is already well understood when $\lambda$ is real using connections to the $\Delta$-regular tree $T$. The key concept in that case is the "occupation ratio" of the tree $T$. This ratio is the contribution to $Z_T(\lambda)$ from independent sets containing the root of the tree, divided by $Z_T(\lambda)$ itself. If $\lambda$ is such that the occupation ratio converges to a limit, as the height of $T$ grows, then there is an FPTAS for approximating $Z_G(\lambda)$ on a graph $G$ with maximum degree $\Delta$. Otherwise, the approximation problem is NP-hard. Unsurprisingly, the case where $\lambda$ is complex is more challenging. Peters and Regts identified the complex values of $\lambda$ for which the occupation ratio of the $\Delta$-regular tree converges. These values carve a cardioid-shaped region $\Lambda_\Delta$ in the complex plane. Motivated by the picture in the real case, they asked whether $\Lambda_\Delta$ marks the true approximability threshold for general complex values $\lambda$. Our main result shows that for every $\lambda$ outside of $\Lambda_\Delta$, the problem of approximating $Z_G(\lambda)$ on graphs $G$ with maximum degree at most $\Delta$ is indeed NP-hard. In fact, when $\lambda$ is outside of $\Lambda_\Delta$ and is not a positive real number, we give the stronger result that approximating $Z_G(\lambda)$ is actually #P-hard. If $\lambda$ is a negative real number outside of $\Lambda_\Delta$, we show that it is #P-hard to even decide whether $Z_G(\lambda)>0$, resolving in the affirmative a conjecture of Harvey, Srivastava and Vondrak. Our proof techniques are based around tools from complex analysis - specifically the study of iterative multivariate rational maps

Foreign and Domestic Bank Participation in Emerging Markets: Lessons from Mexico and Argentina

The Asian Crisis has highlighted the importance of strong domestic financial systems in overall economic development and stabilization. Less agreement is evident on the role of foreign banks in achieving this goal. We explore this issue by studying bank-specific data on lending by domestically- and foreign-owned banks in Argentina and Mexico. We find that foreign banks generally have had higher loan growth rates than their domestically-owned counterparts, with lower volatility of lending, contributing to lower overall volatility of credit. Additionally, in both countries, foreign banks show notable credit growth during crisis periods. In Argentina, the loan portfolios of foreign and domestic privately-owned banks are similar, and lending rates analogously respond to aggregate demand fluctuations. In Mexico, foreign and domestic banks with lower levels of impaired assets have similar loan responsiveness and portfolios. State-owned banks (Argentina) and banks with high levels of impaired assets (Mexico) have more stagnant loan growth and weak responsiveness to market signals. Overall, these findings suggest that bank health, and not ownership per se, is the critical element in the growth, volatility, and cyclicality of bank credit. Diversity in ownership appears to contribute to greater stability of credit in times of crisis and domestic financial system weakness.