The Effects of Interest Rates on Mortgage Prepayments

Three main types of mortgages are fixed interest contracts which automatically fall due on the sale of a dwelling, fixed rate loans which are assumable by a buyer, and floating rate instruments. When interest rates rise, the fall in the economic value of these assets in savings and loan associations' portfolios varies from one form of mortgage to another. For either of the fixed interest rate contracts, the cash flow from the mortgage is constant as long as it has not been prepaid. If the interest rate rises,the homeowner has a nominal capital gain, since his loan is then at a below market interest rate. He would therefore be less likely to prepay. The fall in the savings and loans' net worth arises from two factors: (1) the interest rate differential for mortgages of a fixed duration, and (2) the endogenous lengthening of the duration.This paper is an attempt to measure the dependence of the duration of mortgages on the implicit unrealized capital gain of mortgage holders resulting from interest rate changes. Our estimate is based on a sample of 4,000 mortgages issued in California which were active in 1975. We follow their payment history from 1975 to 1982. Using a Proportional Hazards Model, we estimate the percentage reduction in prepayment probability associated with interest rate changes. Our results indicate that for due-on-sale fixed interest rate mortgages, a sudden increase in the interest rate from 10 to 15 percent would induce a 23 percent loss in the economic value of the mortgage. If the mortgage were assumable,this loss would be 28 percent. Correspondingly, the 6-year average time to repayment of mortgages at a constant interest rate would be lengthened to nine years for due-on-sale mortgages, and 13-1/2 years for assumable ones.

Nondecoupling of Maximal Supergravity from the Superstring

We consider the conditions necessary for obtaining perturbative maximal supergravity in d dimensions as a decoupling limit of type II superstring theory compactified on a (10-d) torus. For dimensions d=2 and d=3, it is possible to define a limit in which the only finite-mass states are the 256 massless states of maximal supergravity. However, in dimensions d>=4, there are infinite towers of additional massless and finite-mass states. These correspond to Kaluza-Klein charges, wound strings, Kaluza-Klein monopoles, or branes wrapping around cycles of the toroidal extra dimensions. We conclude that perturbative supergravity cannot be decoupled from string theory in dimensions >=4. In particular, we conjecture that pure [script N]=8 supergravity in four dimensions is in the Swampland

Spinor fields without Lorentz frames in curved spacetime using complexified quaternions

Using complexified quaternions, a formalism without Lorentz frames, and therefore also without vierbeins, for dealing with tensor and spinor fields in curved spacetime is presented. A local U(1) gauge symmetry, which, it is speculated, might be related to electromagnetism, emerges naturally.Comment: 14 pages; v2: minor corrections; v3: note added concerning unified treatment of local Lorentz transformations and local U(1) gauge transformations; v4: published in J. Math. Phys. 50 083507 (2009

The String Coupling Accelerates the Expansion of the Universe

Generic cosmological models in non-critical string theory have a time-dependent dilaton background at a late epoch. The cosmological deceleration parameter Q_0 is given by the square of the string coupling, g_s^2, up to a negative sign. Hence the expansion of the Universe must accelerate eventually, and the observed value of Q_0 coresponds to g_s^2 ~ 0.6. In this scenario, the string coupling is asymptotically free at large times, but its present rate of change is imperceptibly small.Comment: 7 page

The State of the Parties (Seventh Edition)

Continuing a three-decade tradition, The State of the Parties 7th edition brings together leading experts to evaluate change and continuity in American electoral politics. Political parties in America have never been more contentious and divided than they are right now. Even splits within the parties themselves have the power to elevate relatively unknown candidates to power and topple established incumbents. With sections devoted to polarization and the electorate, polarization and political elites, tea party politics, super PACS, and partisan resources and partisan activities, the contributors survey the American political landscape. They pay special attention to polarization between and within the parties in the aftermath of the 2012 election, demographic changes to America\u27s political parties, the effects of new media and campaign finance laws on national and local electoral results, the Tea Party\u27s rise and, as always, the implications of all these factors on future policymaking and electoral prospects. The State of the Parties 7th edition offers an indispensable guide to American politics for scholars, students, and practitioners.https://ideaexchange.uakron.edu/state_of_the_parties7/1000/thumbnail.jp

The State of the Parties 2018 (Eight Edition)

The State of the Parties 2018 brings together leading scholars of parties, elections, and interest groups to provide an indispensable overview of American political parties today. The 2016 presidential election was extraordinary, especially the unexpected nomination and election of Donald Trump to the White House. What role did political parties play in these events? How did the party organizations fare? What are the implications for the future? Scholars and practitioners from throughout the United States explore the current state of American party organizations, constituencies and resources at the national, state and local level.https://ideaexchange.uakron.edu/state_of_the_parties8/1000/thumbnail.jp

The Warm Ionized Medium in the Milky Way and Other Galaxies

Observations of the "Warm Ionized Medium" (or, equivalently, the "Diffuse Ionized Gas") of the local ISM, the Perseus arm in the Milky Way, and also in several other galaxies show strong [NII]6563 (~H-alpha in some cases) and [SII]6717/[NII]6583 = 0.6 - 0.7 in all locations and objects. Other line ratios (e.g., [O III]5007/H-beta) vary considerably. Simple photoionization models reproduce the observed spectra, providing extra heating beyond that supplied by photoionization is assumed (Reynolds, Haffner, & Tufte 1999). With observed gas-phase abundances (not solar), the line ratios in the local arm at b = 0 deg are fitted with no extra heating and (S/H) = 13 ppm (solar is 20 ppm). Local gas observed at b = -35 deg requires extra heating of about gamma = 0.75, where gamma is the extra heating in units of 10^{-25} erg H^{-1} s^{-1}. In the Perseus arm, there are similar results, with a domposition consistent with the Galactic abundance gradient. The requirements for NGC 891 are similar to the Perseus arm: little or no extra heating at |z| = 1 kpc and gamma 3 at 2 kpc. In NGC 891 there is also an increase of 5007/H-alpha with |z| that can only come about if most of the ionizing radiation is supplied by stars with T~50000 K. Either their radiation must propagate from the plane to high |z| through very little intervening matter, or else the stars are located at high |z|. The total power requirement of the extra heating is <15% of the photoionization power. [O~II]3727/H-beta can serve as a useful diagnostic of extra heating, but [S~III] 9065,9531/H-alpha is not useful in this regard.Comment: 32 pages, including 2 figures. To appear in November 20 Ap

HI Emission and Absorption in the Southern Galactic Plane Survey

We present preliminary results from the Southern Galactic Plane Survey (SGPS) Test Region and Parkes data. As part of the pilot project for the Southern Galactic Plane Survey, observations of a Test Region (325.5 deg < l < 333.5 deg; -0.5 deg < b < 3.5 deg) were completed in December 1998. Single dish observations of the full survey region (253 deg < l < 358 deg; |b| <1 deg) with the Parkes Radio Telescope were completed in March 2000. We present a sample of SGPS HI data with particular attention to the smallest and largest scale structures seen in absorption and emission, respectively. On the large scale, we detect many prominent HI shells. On the small scale, we note extremely compact, cold clouds seen in HI self-absorption. We explore how these two classes of objects probe opposite ends of the HI spatial power spectrum.Comment: 9 pages, 3 embedded postscript & 4 jpeg figures. Presented at the Astronomical Society of Australia, Hobart, Tasmania, July 4-7 2000. To appear in PASA Vol. 18(1