Publications

2006

• Arbitrage with Fixed Costs and Interest Rate Models
  
  • Jouini Elyès
  • Napp Clotilde
  Journal of Financial and Quantitative Analysis, Cambridge University Press, 2006, 41 (4), pp.889-913. We study securities market models with fixed costs. We first characterize the absence of arbitrage opportunities and provide fair pricing rules. We then apply these results to extend some popular interest rate and option pricing models that present arbitrage opportunities in the absence of fixed costs. In particular, we prove that the quite striking result obtained by Dybvig, Ingersoll, and Ross (1996), which asserts that under the assumption of absence of arbitrage long zero-coupon rates can never fall, is no longer true in models with fixed costs, even arbitrarily small fixed costs. For instance, models in which the long-term rate follows a diffusion process are arbitrage-free in the presence of fixed costs (including arbitrarily small fixed costs). We also rationalize models with partially absorbing or reflecting barriers on the price processes. We propose a version of the Cox, Ingersoll, and Ross (1985) model which, consistent with Longstaff (1992), produces yield curves with realistic humps, but does not assume an absorbing barrier for the short-term rate. This is made possible by the presence of (even arbitrarily small) fixed costs. (10.1017/S0022109000002684)
  DOI : 10.1017/S0022109000002684
• The impact of financial constraints on innovation: evidence from French manufacturing firms
  
  • Savignac Frédérique
  Cahiers de la Maison des Sciences Economiques, UMS 1814 Centre de documentation de la Maison des Sciences Economiques, 2006. This paper examines the impact of financial constraints on innovation for established firms. We make use of a qualitative indicator of the existence of financial constraints based on firms' own assessment obtained thanks to a French specific survey. Thus, the existence of financial constraints for innovation is measured by a direct indicator whereas previous studies rely on proxies (like the cash-flow sensitivity) subject to interpretation problems. The descriptive analysis of balance sheet structures reveals that innovative firms without financial constraints have the best profile in terms of economic performances, financing structure and risk whereas non innovative firms facing financial constraints have the poorest profile. From the econometric point of view, the probabilities of implementing innovative projects and of facing financial constraints are simultaneously estimated by a recursive bivariate probit model to account for the endogeneity of the financial constraint variable. We then find that firms having innovative projects face financial constraints that significantly reduce the likelihood that they implement their innovative investment. The probability of facing financing constraints is explained by firms' ex ante financing structure and economic performances, by industry sector and it decreases with firms' size.