Quasar Lenses and Galactic Streams: Outlier Selection and GAIA Multiplet Detection

I describe two novel techniques originally devised to select strongly lensed quasar candidates in wide-field surveys. The first relies on outlier selection in optical and mid-infrared magnitude space; the second combines mid-infrared colour selection with GAIA spatial resolution, to identify multiplets of objects with quasar-like colours. Both methods have already been applied successfully to the SDSS, ATLAS and DES footprints: besides recovering known lenses from previous searches, they have led to new discoveries, including quadruply lensed quasars, which are rare within the rare-object class of quasar lenses. As a serendipitous by-product, at least four candidate Galactic streams in the South have been identified among foreground contaminants. There is considerable scope for tailoring the WISE-GAIA multiplet search to stellar-like objects, instead of quasar-like, and to automatically detect Galactic streams.Comment: MNRAS subm. 21/04, revised version after referee report. 10 pages, 5 figure

Discretionary Fiscal Policies over the Cycle: New Evidence based on the ESCB Disaggregated Approach

This paper explores how discretionary fiscal policies on the revenue side of the government budget have reacted to economic fluctuations in European Union countries. For this purpose, it uses data on legislated revenue changes and structural indicators provided twice per year by National Central Banks of European Union countries in the ESCB framework for analysing fiscal policy. The analysis is based on the estimation of fiscal policy rules linking these measures of legislated fiscal policy changes to the output gap and other control variables. Then, baseline results are compared with regression estimates where variations of cyclically-adjusted indicators are used as proxy for discretionary fiscal policies, as conventionally proposed in the empirical literature on fiscal policy. Results suggest that, overall, legislated changes in taxes and social security contributions have responded in a strongly pro-cyclical way to the business cycle, while commonly-used cyclical-adjustment methods point to a-cyclicality. JEL Classification: E62, E65, H20cyclical sensitivity, Discretionary fiscal policies, ESCB disaggregated framework, government revenues, legislation changes, narrative approach

"Prices for Paintings by African American Artists and Their Contemporaries: Does Race Matter? (Revision of Working Paper No. 2006-06)"

This paper investigates the extent that economic markets have incorporated mainstream artistic acceptance of African American art. Price levels and movements for paintings by African American artists versus their white contemporaries are compared using auction data from 1972 to 2004. Means in the aggregate as well as individually are found to be significantly lower for African American artists in almost every case. Hedonic regressions are used to refine the statistical analysis by controlling for factors characterizing the painting and auction environment. In the regressions significant differences persist between the two groups with African American artists experiencing lower price levels but higher price appreciation throughout the period. The price gap thus appears to be narrowing indicating a possible convergence of economic reality and artistic appreciation. In addition, the higher investment returns for paintings by African American artists made them a relatively profitable art niche in recent years and possibly for the future since economic values have not completely converged for the two groups.Economics of Art, Painting Prices, African American Painters, Hedonic Regression

Can Fiscal Policy Stimulus Boost Economic Recovery?

We assess the role played by fiscal policy in explaining the dynamics of asset markets. Using a panel of ten industrialized countries, we show that a positive fiscal shock has a negative impact in both stock and housing prices. However, while stock prices immediately adjust to the shock and the effect of fiscal policy is temporary, housing prices gradually and persistently fall. Consequently, the attempts of fiscal policy to mitigate stock price developments (e.g. via taxes on capital gains) may severely de-stabilize housing markets. The empirical findings also point to significant fiscal multiplier effects in the context of severe housing busts, which gives rise to the importance of the implementation of fiscal stimulus packages. In addition, our results suggest that when governments run a budget deficit, they place an upward pressure on real interest rates, which "crowds-out" private consumption and investment. In contrast, during bust periods, unexpected variation in the fiscal stance crowds-in private spending, which reflects the "direct" and "indirect" effects of policy actions impact arising from a downward movement in real interest rates and an upward revision in price level expectations.Fiscal policy, asset prices, panel VAR.

Investment Returns and Risk for Art: Evidence from Auctions of American Paintings

The literature on return and risk for investment in paintings is extended by disaggregating for artist, genre, and quality. A hedonic log price model generates yearly price indices and shadow values for painting characteristics using a large sample of U.S. artists sold at auction from 1971 to 1996. Overall returns to holding paintings are low, and have high annual variation although disparities are found across categories. High quality paintings show the highest returns, second only to equities, and are not offset by higher risk. Buying the highest quality superstar paintings seems to be the best overall investment strategy.Art; Artist

Optical properties of Ge-oxygen defect center embedded in silica films

The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation in the 10-300 K temperature range. This center exhibits two luminescence bands centered at 4.3eV and 3.2eV associated with its de-excitation from singlet (S1) and triplet (T1) states, respectively, that are linked by an intersystem crossing process. The comparison with results obtained from a bulk Ge-doped silica sample evidences that the efficiency of the intersystem crossing rate depends on the properties of the matrix embedding the Ge-oxygen defect centers, being more effective in the film than in the bulk counterpart.Comment: 10 pages, 3 figures, in press on J. Non cryst. solids (2007

How do Banking Crises Impact on Income Inequality?

We show that banking crises have an important effect on income distribution: inequality increases before banking crisis episodes and sharply decline afterwards. We also find that,while a large government size does not per se seem to reduce inequality, a rise in financial depth (i.e. better access to credit provided by the banking sector) contributes to a more equal distribution of income.Inequality, banking crisis, financial depth, government size.