Disclosed are compositions which include an ethylene polymer derived from at least one polar monomer with one or more ester groups, which polymerize with ethylene, (e.g., a copolymer, or low molecular weight copolymer having a relatively high melt index, derived from ethylene and vinyl acetate and/or a copolymer, or low molecular weight copolymer having a relatively high melt index, derived from ethylene and «-buty! acrylate) and a rosin ester, The rosin ester can have a low hydroxy! number (e.g., a hydroxy! number six or five or less), a low acid number (e.g., an acid number of ten or less), a relatively low PAN number (e.g., a PAN number less than twenty-two or in between eight and twenty), a relatively high third moment or third power average molecular weight (Mz), (e.g., an Mz value in between 2500 and 12000 g/mol), a low sulfur content (e.g., a sulfur content lower than 600 ppm prior to antioxidant addition) or combinations thereof. The compositions can exhibit a high heat stress resistance (e.g., a heat stress pass temperature value higher than 52 °C or in between 48 °C and 60 °C) and/or improved viscosity stability and/or color stability upon thermal aging and/or improved compatibility.