Excerpt: To bolster pensions and avoid a taxpayer bailout of the PBGC, the Labor Dept. proposed legislation in January that would require many companies to hike their pension-fund spending sharply. The Bushies also want employers to stop using interest-rate assumptions that help smooth out the annual fluctuations in plan assets and liabilities. The Administration says this has added to the shortfall by allowing companies to get away with making smaller contributions to the plans.