The markets saw another week of mixed earnings reports, but got some positive news with strong U.S. jobs data. Earnings, as usual, were mixed this week, with a number of companies, including Exxon Mobil (XOM), ConocoPhillips (COP), Phillips 66 (PSX), and Time Warner (TWX), turning in results that beat analysts' estimates, while Chevron (CVX), MetLife (MET), and CVS Caremark (CVS) missed expectations. Markets were up on Friday morning, following the release of positive U.S. jobs growth data. U.S. nonfarm payrolls added 288,000 jobs in April, high above the 210,000 that was expected by economists. The unemployment rate fell to 6.3%, a five-and-a-half year low. In the bond markets, 10-Year Treasury yields fell this week to 2.63 to close out Thursday, after starting the week at 2.70. Below, we look at all of Moody's municipal bond upgrades and downgrades from the past week.

Upgrades

• Travis County Municipal Utility District No. 6, TX: Moody's upgraded this county to A3 from Baa1. The upgrade to the A3 rating reflects the small, but affluent tax base, located in the Barton Creek area near Austin; a healthy financial reserve position; and an elevated but manageable debt burden.
• Perryton Independent School District, TX: Moody's upgraded this school district to Aa3 from A1. The upgrade to Aa3 primarily reflects the district's strengthening financial performance, a manageable debt profile, and a low pension burden. The tax base is moderately sized and the local economy is expanding, but the district's otherwise rural service area is dependent on a recent boom in oil and gas activity.
• Southold Fire District, NY: Moody's upgraded this fire district to Aa2 from Aa3. The upgrade to Aa2 rating captures the district's moderately sized tax base with above-average wealth levels, strong financial position, stable operations with minimal revenue or expenditure volatility, and modest debt burden that is rapidly amortized.
• Olton Independent School District, TX: Moody's upgraded this school district to A2 from A3. The upgrade reflects the district's solid financial reserves and liquidity with a large pre-planned draw, and a modestly-sized, somewhat limited and moderately concentrated tax base. The rating also incorporates the district's low debt profile, minimal pension liabilities, and relatively low socioeconomic measures.
• Johnson City Independent School District, TX: Moody's upgraded this school district to Aa3 from A1. The upgrade to Aa3 reflects the district's solid financial reserves and liquidity despite a large planned draw, and a modestly-sized, somewhat limited and moderately concentrated tax base. The rating also incorporates the district's low debt profile, minimal pension liabilities.
• San Marino Unified School District, CA: Moody's upgraded this school district to Aa1 from Aa2. San Marino Unified School District's general obligation rating reflects the strength of the voter-approved, unlimited property tax pledge that secures the debt service levy. Also taken into consideration is the secure nature of debt collection in which the county levies, collects, and disburses the district's property taxes, including the portion restricted for the school district's general obligation debt service.
• Mystic Fire District, CT: Moody's upgraded this fire district to Aa3 from A1. The upgrade to Aa3 from A1 reflects the district's stable financial operations which are supported by healthy reserve levels. The rating also incorporates the limited but essential services provided by the district, as well as the significant economic concentration in the surrounding area. Finally the upgrade factors the minimal outstanding debt of the district which is repaid at a rapid pace.
• Town of Big Flats, NY: Moody's upgraded this town to Aa3 from A1. The upgrade to Aa3 captures the town's modestly sized but healthy tax base that has been growing, the solid financial position bolstered by a favorable sales tax trend, and a low debt burden.
• Bayport, MN: Moody's upgraded this city to Aa3 from A1. The upgrade to Aa3 reflects a solid financial position with sound reserve levels. The rating further reflects a manageable debt position with rapid principal repayment, and a limited tax base.

Downgrades

• Carnegie Institution of Washington, DC: Moody's downgraded this institution to Aa1 from Aaa. The downgrade to Aa1 from Aaa reflects a number of factors which, combined, weaken the institution's credit. The proposed new issuance halves financial resource coverage of debt, Carnegie's financial resources are relatively small compared to peers, and there is heightened business risk associated with the funding and execution of a new telescope project that requires coordination with many partners.
• Miami-Dade County, FL: Moody's downgraded this county's port's outstanding seaport revenue bonds to Baa1 from A3. The rating downgrade to Baa1 is based on the substantial increase in port leverage to complete a large capital improvement plan (CIP), the on-going transformation of the port's debt profile, the much tighter financial margins and lower all-in debt service coverage ratios (DSCRs) going forward, forecasted revenue shortfalls in 2017 and the reliance on sustained volume and revenue growth to achieve forecasted DSCRs.
• Kansas: Moody's downgraded this state's issuer rating to Aa2 from Aa1 and notched ratings to Aa3 from Aa2 on the state's $1.23 billion of outstanding subject-to-appropriation bonds, and $1.6 billion of state highway revenue bonds from Aa1 to Aa2. The downgrade reflects Kansas' relatively sluggish recovery compared with its peers, the use of non-recurring measures to balance the budget, revenue reductions (resulting from tax cuts) which have not been fully offset by recurring spending cuts, and an underfunded retirement system for which the state is not making actually required contributions.
• City of Wyoming, MI: Moody's downgraded this city's outstanding sewerage disposal revenue debt to A2 from A3. The downgrade to A2 reflects the system's failure to meet sum sufficiency in fiscal 2013 and management's unwillingness to increase rates sufficiently to meet legal covenants per bond resolution.
• City of Des Moines, IA: Moody's downgraded this city to Aa2 from Aa1. The downgrade of the city's GO rating to Aa2 primarily reflects the city's narrow operating reserves, below average income indicators and elevated debt burden. Despite these challenges, the city's large and stable tax base, key roles as the state capital and the primary economic and population center of the State of Iowa (Aaa/stable outlook), and recent history of surplus operations support its Aa2 rating.
• Hopkins County Hospital District, TX: Moody's downgraded this hospital district to B1 from Ba3. The rating downgrade is attributable to a weakening of HCHD's balance sheet through a marked decline in liquidity and the continuation of low operating performance with declines in admissions and variability in other volume metrics.
• Livonia Public Schools School Districts, MI: Moody's downgraded these school districts to A2 from A1. The A2 rating reflects the district's narrow general fund position, declining enrollment, and above average debt levels with expected future borrowing. Also incorporated in the recommendation is the district's sizable but depreciating tax base, above average socioeconomic characteristics, and long term risks posed by exposure to an underfunded cost-sharing retirement plan.
• Berea City School District, OH: Moody's downgraded this school district to A2 from A1. The A2 GO rating reflects the district's very narrow General Fund cash reserves which are expected to gradually improve following five consecutive operating deficits. Also incorporated in the rating is the district's sizable tax base in southern Cuyahoga County (Aa1 stable); average socioeconomic characteristics; declining enrollment trend; average debt burden; and elevated exposure to two significantly underfunded cost-sharing pensions plans.
• Toledo City School District, OH: Moody's downgraded this school district to A2 from A1. The A2 underlying rating incorporates the district's challenged economic and demographic environment as indicated by above average unemployment, a negative population trend, declining enrollment, and a multi-year trend of tax base depreciation.
• City of Seven Hills, OH: Moody's downgraded this city to Aa3 from Aa2. The Aa3 rating reflects maintenance of a satisfactory financial position despite narrowing of reserves over the past five years. The rating also incorporates a moderate tax base with above-average wealth levels and manageable debt burden.