Developmental changes in word recognition threshold from two to five years of age in children with different middle ear status

The aims were to: (1) provide word recognition thresholds (WRTs) at 31, 43, and 61 months of age; (2) investigate developmental changes over time; (3) investigate the relationship between OME and WRT, and (4) investigate the relationship between WRT and hearing thresholds. Around 1000 children were tested longitudinally as part of the ALSPAC study, using an adaptive measure of word recognition in quiet. Mean WRTs were 28, 23, and 23 dB (A) at 31, 43, and 61 months, respectively. Normal auditory development is associated with a mean improvement in WRT of 5 dB between age 31 and 61 months. There was a mean increase in WRT of 5 dB and 15 dB when OME was present in one and two ears, respectively. Thus, both unilateral and bilateral OME results in a detrimental effect on hearing ability for speech. Additionally, early and ‘persistent’ OME is associated with greater disability. However by 61 months, previous OME status was not significant. To our knowledge, this is the largest longitudinal study reporting WRT in preschool children with different middle ear status

The Value of Building Codes

We present a double moral hazard model to study the impact of building codes on the safety/quality level chosen by the builder and the level of care expended by the buyer. We show that codes can be a mechanism to implement the first-best solution provided: (1) The code prescribes the optimum safety level, (2) The code uses the efficient technology to achieve the optimum safety level, and (3) The courts use Negligence Rule as the liability rule. We argue, however, that codes in general do not use the efficient technology. We provide an alternative mechanism to implement the first-best solution. This mechanism is a contract between the builder and the buyer that specifies the level of safety jquality to be expended by the builder. We prove that the contract is a more effective and more efficient mechanism than are the building codes. Copyright American Real Estate and Urban Economics Association.